Can't open the wrist watch case

The Proper way is with a "watch case wrench". They can be purchased for a few dollars on Amazon and E-bay. In most cases unless you are changing many watch batteries the best option is to call around to local jewelers and pawn shops and ask how much to replace a watch battery. In my town it ranges from $30 to as little as $5.99 battery included.

The back of your watch is attached in one of two ways. Look at the watch back. If it's smooth all around the circumference of the back, you have a snap-fit back. If, however, you see little notches cut into the edges--if they were extended, it would make the back look like a pizza that's been cut into slices--then you have a back that screws on and off. Pictures I've seen of your specific watch suggest to me that you have a snap-fit case back, though I'll include instructions about a screw-on back, just in case I'm wrong.

A snap-fit case back often has a small (very small) raised section at one spot of the rim; this is so you can insert a tool called a case knife and pop the back off. If you don't see that small raised section, you'll need to wiggle the blade of your case knife under the edge and gently apply leverage from there--it's usually easiest by one of the watch lugs, as opposed to near the watch crown. If you don't have a case knife, you can often use a thin (but tough!) knife blade to do the same thing. Remember, though, that applying this much force through a knife blade can distort or take a chunk out of your edge, so be prepared to sacrifice a knife or be prepared to re-sharpen it after this exercise. A screwdriver does not work very well; the blades are typically too narrow to provide good leverage without distorting the case back, and they may even gouge into the watch body. Avoid using them for this purpose. To increase the water resistance of watches, modern snap-fit case backs are often very tightly fitted--they're tough to get off, and even tougher to push back into position. I would not be surprised if you would need a jeweler's press to get the back of this watch back into position.

If, on the other hand, you have a case back with notches in it, you will need to unscrew the back of the watch. You'll need a special wrench to do this. There are lots of makers and models from a basic $5 "watch crab" to a $100 workbench-mounted device that works on all kinds of watches, including Rolexes. Again, because screw backs are usually tightly fastened to increase water resistance, simply using a pair of needle-nose pliers in the ridges probably won't work. Nor will using a screwdriver in one notch--these backs are designed to move when equal pressure is applied around the edges, and applying force in one area only locks things up. Under no circumstances try to pry off the back if you have a screw back -- this will damage the threads, and you'll probably never be able to get the watch back together again.

You can find case knives and case wrenches at many jewelry supply stores, mail order supply houses like Otto Frei (http://www.ottofrei.com/store/home.php?cat=296 will take you right to the watch repair tools), and on eBay. However, if you're near a Harbor Freight store, they sell a "watch battery changing kit" and jeweler's press for a pretty reasonable price. These aren't the ultra-high quality tools that a professional jeweler would use, but they'll be perfectly fine for changing the occasional battery for many years. I've probably closed 100+ watches using the inexpensive press I got from there.

If you can't close the watch case with your bare hands and don't have access to a case press, your safest bet may be to go to a jewelry store or jewelry counter in a department store and ask if they could close the back for you with the proper tool. You may have to tip them a few dollars, but that is still far cheaper than the cost of replacing a broken watch crystal.

The back of your watch is attached in one of two ways. Look at the watch back. If it's smooth all around the circumference of the back, you have a snap-fit back. If, however, you see little notches cut into the edges--if they were extended, it would make the back look like a pizza that's been cut into slices--then you have a back that screws on and off. Pictures I've seen of your specific watch suggest to me that you have a snap-fit case back, though I'll include instructions about a screw-on back just in case I'm wrong.

A snap-fit case back often has a small (very small) raised section at one spot of the rim; this is so you can insert a tool called a case knife and pop the back off. If you don't see that small raised section, you'll need to wiggle the blade of your case knife under the edge and gently apply leverage from there--it's usually easiest by one of the watch lugs, as opposed to near the watch crown. If you don't have a case knife, you can often use a thin (but tough!) knife blade to do the same thing. Remember, though, that applying this much force through a knife blade can distort or take a chunk out of your edge, so be prepared to sacrifice a knife or be prepared to re-sharpen it after this exercise. A screwdriver does not work very well; the blades are typically too narrow to provide good leverage without distorting the case back, and they may even cutt a gouge into the watch body. Avoid using them for this purpose. To increase the water resistance of watches, modern snap-fit case backs are often very tightly fitted--they can be tough to get off, but they're even tougher to push back into position. I would not be surprised if you would need a jeweler's press to get the back of this watch back into position.

If, on the other hand, you have a case back with notches in it, you will need to unscrew the back of the watch. You'll need a special wrench to do this. There are lots of makers and models from a basic $5 "watch crab" to a $100 workbench-mounted device that works on all kinds of watches, including Rolexes. Again, because screw backs are usually tightly fastened to increase water resistance, simply using a pair of needle-nose pliers in the ridges probably won't work. Nor will using a screwdriver in one notch--these backs are designed to move when equal pressure is applied around the edges, and applying force in one area only locks things up. Under no circumstances try to pry off the back if you have a screw back -- this will damage the threads, and you'll probably never be able to get the watch back together again.

You can find case knives and case wrenches at many jewelry supply stores, mail order supply houses like Otto Frei (http://www.ottofrei.com/store/home.php?cat=296 will take you right to the watch repair tools), and on eBay. However, if you're near a Harbor Freight store, they sell a "watch battery changing kit" and jeweler's press for an extremely reasonable price. These aren't the ultra-high quality tools that a professional jeweler would use, but they'll be perfectly fine for changing the occasional battery for many years. I've probably closed 100+ watches using the inexpensive press I got from there.

If the back of your watch is completely smooth, the odds are that it has a snap-fit case. Screw-back wristwatch cases generally have small indentations in the case back into which you fit a case wrench. Rolexes have an elaborately ridged edge to their case backs and take a special wrench. A few early water-resistant watches have little screws that hold the front and back of the case together, but these are usually quite obvious, and you didn't mention them in your description.

Most "fancy" ladies watches of the 40s, 50s, and 60s, had snap-back cases. To open one of these without damaging the case, I recommend gently working a decent quality case knife into the crack where the case back joins the case and gently levering up. If the case is really snug, you may need to do this in a few places to gradually pry apart the case halves. Often, the best place to do this is at the lugs, because they offer a leveraging point. I don't recommend doing this with a sharp knife blade, as the resistance from the case will probably damage the knife edge, and if the knife slips, it can easily scratch the case. If you don't have a case knife, try using the rounded edge of a butter or table knife. Do not use a flathead screwdriver blade, as the short width of that tool can easily place so much pressure on a small section of the case that it deforms and can never be made to look good again.

Usually you would need a watchmakers press for closing the watch back. Without proper tools it is quite difficult, but you can try the following. Take a leather belt and lay it flush on an even, solid surface (stable table will do). Undo the strap (both ends) from watch case by pushing spring bars inwards with pen knife. Lay the watch crystal face down on the leather belt. Belt must be wider than watch itself and the leather must be quite hard and even, not soft. Find the small groove on watch case back and align it very carefully to the watch's winding stem, so, the stem goes directly in the middle in protrusion. Slightly push the case back into the watch case at that groove point and gradually apply pressure with fingers going all way around the case back. Use your body weight if needed. You should hear "click" sound when the case back jumps in to place. If this does not work, there is no other way, but to go and see watchmaker. Hope it will work for you.

You need a watchmakers knife or caseback opening tool to open your watch.
1)If your watch has screwdown back, there should be grooves in caseback where you have to put in opener and unscrew that caseback.
2)If your watch has a 'clip-on' caseback, you have to carefuly examine the caseback and find the groove between caseback and watch case (it is called 'the lip'). This is the right point where to insert the blade of wtchmakers knife and open it using pressure and lever action.
3)The safest, but dearest way is to visit your nearest watch repair shop and ask for battery replacement. You may ask the watchmaker to show you how to do that, so, in future you can do that yourself.
Do not forget to rate, please.

First you have to get an eyeglass and examine watch caseback. Can you see the joint or is it monoblock? If there is joint, get strong knife and press into it. Some of watch casebacks are very tight, so, apply great pressure but do not let the blade slip or you will damage the movement.
If the case is monoblock, then you have to open it from dial side.
Be very carefull when doing it as any slip of the blade will damage your watch.

Good luck.

If you are shure that your watch has a removable caseback then you have to use special case opening tool (looks like knife with very short and curved blade). Insert blade into the groove and applying great and steady pressure turn the opener upwards. The back should come off. Make sure the blade doesn't slip, oterwise you will damage the movement.
As your watch model is obsolete, I compared it to MQ24-7BLL and find that this movement should be opened from the front- First the glass must be removed, then stem with crown and then movement itself. In this case you will not be able to do it yourself as special tool for removing glass is needed. If you will try it anyway, you will end up with snapped glass as it is set with great pressure to make case water resistant.

Regards

Arthur

For that you need tool called watch caseback opener. It looks like knife, only the blade is very short, curved and hardened Plenty on ebay for around 5 GBP.
Ordinary knifes wont work as they aren't hard enough and you can damage the watch and injure yourself.
If you gonna try to use chisel and hammer action, then you will damage your watch definetely.
Why don't use watchmaker services? Battery replacements are not very costly.

Regards

Arthur

battery change