I need step by step on putting blade guard back on Makita LS1013

https://www.google.com/search?q=How+to+work+makita+ls1013+without+controller+device&oq=How+to+work+makita+ls1013+without+controller+device&aqs=chrome..69i57&sourceid=chrome&ie=UTF-8

I have attached a link with the parts breakdown and the owners manual both in PDF format.
The parts breakdown should help you, if not let me know and I'll try to talk you through it.
Makita Products Tool Support

Simple, unpug tool. Remove blade and back flange. Remove circlip and lift off guard. Unclip spring. Re-fit new guard. Refit spring and circlip. Refit blade.

I don't have this particular model in my shop right now but almost all circular saws work like this. From the blade side of the saw, the spring attaches to a hole in the blade guard usually around the two to three o'clock position. With the blade guard correctly positioned on the saw, wrap the spring clockwise around the bottom of the hub and back up the nine o'clock side. There is another hole or tab inside the top of the upper blade guard somewhere around the twelve to two o'clock position. Hook the end of the spring there and test the guard for free movement throughout it's range of motion.

Be sure the saw is switched off and unplugged. Use the Makita socket wrench on the side of the saw base if you still have it. If not make sure you use a socket or wrench that fits the bolts properly so you get them off and back on without damaging them. Lock the handle in the up position with the stopper pin. Loosen the hex bolt holding the center cover in place, this will let you raise the guard and center cover so you can get at the blade bolt. There is a button on the back side of the blade guard that locks the spindle. Push and hold the button in and turn the blade until it locks in place. Using the socket wrench, turn the blade bolt clockwise or in the same direction the blade turns while cutting to remove it, the outer flange and blade. Put the new blade on (check that the direction of the arrow on the blade is the same as on the guard), the outer flange and blade bolt. Use the spindle lock to get the bolt on tight. Return the center cover to it's original position and tighten it's hex bolt. Turn the blade by hand to make sure the spindle lock released then pull the stopper pin and make sure the blade guard works properly.

If you want to replace the plastic cover there is a screw towards the front of the saw that must be removed and then the bolt at the back loosened and the guard will pull off. If you need more info get back to me with the other questions and I will try and help

http://www.toolpartsdirect.com/cgi-bin/schematic.cgi/makita/LS1013/

The above link, is a complete exploded parts diagram. Below is a generic How to replace the spindle & bearings.
http://www.woodworkforums.com/f170/replacing-spindle-bearings-127932/

You will need to lock, the spindle, and use a puller, and maybe even heat to get it apart depending on how worn damage etc?
below is a wiki for another type but may help?
http://wiki.owwm.com/Default.aspx?Page=1214ArborBearings&AspxAutoDetectCookieSupport=1

A spindle repair service below.
http://www.gtsaz.com/Spindle_Rebuild_Repair.html

Theres a nut on the guard you need to loosen. Guard will then open enough to change blade. if you want to remove it completely theres a phillips srew you also need to remove.

Oh, you got it off. I bet you can put it back on again.
It's much easier if you take the blade off first. Then you'll be able to reach inside when you need to. Be patient, don't force it, and make sure when you get the spring reconnected properly that the guard moves freely out of the way when you chop, and returns when you raise the saw back up.
It's a bit of a trick, but I bet you can manage it..It's been awhile, but it seems to me there's a way to get the bolt started before you engage the tension on the spring...I'd have to have it in my hands to say exactly.
Here's a link to the exploded parts view at the Makita site, just in case. And it might help to have an extra pair of hands, or a piece of duct tape to hold the guard in place when you go to put the blade back on.