Yellowing trim pieces surrounding microwave

Found this post on another fixya-type site: below is the link..
Here's a repeat of Kai's instructions so you don't have to scroll down. I just replaced mine and it was a snap. Just a few Phillips screws and a few tugs. No need to pull the unit completely out as you can access the bulb after it's about half way. No need to disconnect any wiring harness except pulling the bulb out of its socket. I used the 10w (G4 12V) replacement bulb from Home Depot at $6. The light is a bit brighter but there've been no problems with fuses.

1) Turn off power to the unit
2) Open the lower oven door
3) Remove the side trim screws and pull the trims down and out.
4) Remove 2 screws on the sides of the control panel.
5) Open the Microwave door. Remove the 3 screws on the Air Vent Plastic Cover on top of the microwave. You can then remove the Air Vent Cover by pushing the control panel up and pull out slightly at the bottom.
6) Remove the 4 screws on the Air Vent Plastic Cover on top of the lower oven and remove the Air Vent Cover. (You may have to remove the left under side bracket of the Microwave door temporarily just for the Air Vent Cover to clear the screw of the bracket. Re-secure the side bracket of the Microwave door panel as the front panel may fall)
7) Remove the 2 screws which held the Microwave unit in place behind the Air Vent Cover on step 6.
8) Wiggle the Microwave unit out about half way to expose the light bulb unit on top center
9) Wiring to the Control Panel will prevent you from pulling the Microwave unit out any further. And you don't want to do that as the unit may fall. Space is cramped, but working carefully with pliers you should be able to release the springs which held down the light bulb unit and change the bulb.
http://www.fixed4free.com/answers.php?id=51232

What model?    Is it a 'wall-oven'?  If so, many have trim pieces on the sides that cover actual mounting screws.  Also- these units are extremely heavy and require two people to remove/install. Trim pieces are usually held in by screws accessed with door open. Some trim slides up to release. With trim off mounting screws should be visible. Remove these, and unit should be free.Wiring behind unit can also be shorter than most people think, so have something to set it on.  Please acknowledge this posted solution if helpful-  Have more info if needed- Thanks-- Ed

This worked like a charm ... actually it's easier than you might think. Just a few screws and a few tugs. Give it a shot.. I found a 10W (G4 style ... you'll see the difference when you get to the store) replacement bulb at Home Depot for $6:

1) Turn off power to the unit
2) Open the lower oven door
3) Remove the side trim screws and pull the trims down and out.
4) Remove 2 screws on the sides of the control panel.
5) Open the Microwave door. Remove the 3 screws on the Air Vent Plastic Cover on top of the microwave. You can then remove the Air Vent Cover by pushing the control panel up and pull out slightly at the bottom.
6) Remove the 4 screws on the Air Vent Plastic Cover on top of the lower oven and remove the Air Vent Cover. (You may have to remove the left under side bracket of the Microwave door temporarily just for the Air Vent Cover to clear the screw of the bracket. Re-secure the side bracket of the Microwave door panel as the front panel may fall)
7) Remove the 2 screws which held the Microwave unit in place behind the Air Vent Cover on step 6.
8) Wiggle the Microwave unit out about half way to expose the light bulb unit on top center
9) Wiring to the Control Panel will prevent you from pulling the Microwave unit out any further. And you don't want to do that as the unit may fall. Space is cramped, but working carefully with your fingers or pliers you should be able to release the springs which held down the light bulb unit and change the bulb.

First step: Kill power at breaker.
Second Step: Verfiy power is not on. No lights work, no heat, no sign of any power.
Third step: Check power again.

Now, it is helpful to place a small table in front of the unit, at close to the same height as the opening in the wall. This way, when you get the unit out, you can set it somewhere while you unhook the wires.

When yu open the door, there should be screws along the edge that hold the unit to the wall. Remove these.There could be some along the top & bottom, and you may have to remove a piece of trim to locate these. Mine just had screws on the side.

You may find it easier to remove the door from the front of the unit. The door is usually very heavy, so be ready to catch it, and also, this will make the main unit in the wall lighter to handle.With the door off, you can also sometimes get a better grip.

Pull the unit out, set it on the table described earlier.

Now the dangerous part,
Reach behind and unhook the wires. Probably used wire nuts. Be sure to cap off the bare wires from the wall so there is no danger of shock or shorts if someone were to turn the power back on.

Now you should have a big hole in the wall.

Yes, there is one for both units together. It's in the back of the oven, and you will need to remove the oven from the cabinet to get to the fuse. Turn off the power to the oven first - the fuse is connected to a live wire L2. To get to the mounting screws you'll need to remove left&right trim pieces: open the oven door and you'll see the screws on the trim pieces, they are near the door base. Remove screws and remove trim pieces. The mounting screws are in front of you. The oven is HEAVY, and you'll need to secure it somehow while working on it. The fuse is on the back wall, and looks like a disc, attached with 2 screws, has 2 terminals with 2 or 3 wires coming to them. One of the wires will be red in color. If there is no continuity between the fuse contacts - replace. Good luck.

take the trim peices off. take the screws that hold it to the wall out slidee unit out a little to remove the 2 screws from the consol lift the consol up and off. make sure that you have turned the power off inside the unit you will see a tech sheet that will tell you what that error code means. let me know how it goes the tech sheet is usually on the left side.

Mine is installed also, and I've had to replace the bulb twice. I wised up the second time and installed an access hole where I can pull my microwave out about 6" and access the bulb. I use a 35 watt 120v halogen bulb, with a GY 8.6 base, Lowe's part number 15797. If your's is different, the specs will be stamped on the metal beside the reflector when you remove the sheetmetal. You have to remove the microwave completely from the cabinet and remove the sheetmetal case that surrounds the entire unit. You can then access the lamp socket by looking in from the top. The first time, I took out the reflector with the socket. The bulb can be replaced by removing the two small screws adjacent to the socket on top of the reflector. My access port is a hole cut into the top. I cover the hole with a piece of sheetmetal and two sheetmetal screws. Seems to work just fine. If you do decide to cut a hole, do so with the metal enclosure off and away from the microwave to avoid getting any metal shavings into the machine!
Regards! --W/D--

a number of solutions for your problem a little smaller better then a little larger, iv seen depending on surrounding cabinetry, either wood fill strips, lexan(plastic) strip added as a filler. depending on what the installation guide recommends for opening , that is all that would be required what you fill if with will be a purely asthetic choice

Here is a simpler method from the same website mentioned in solution #1:
1) Turn off power to the unit
2) Open the lower oven door
3) Remove the side trim screws and pull the trims down and out.
4) Remove 2 screws on the sides of the control panel.
5) Open the Microwave door. Remove the 3 screws on the Air Vent Plastic Cover on top of the microwave. You can then remove the Air Vent Cover by pushing the control panel up and pull out slightly at the bottom.
6) Remove the 4 screws on the Air Vent Plastic Cover on top of the lower oven and remove the Air Vent Cover. (You may have to remove the left under side bracket of the Microwave door temporarily just for the Air Vent Cover to clear the screw of the bracket. Re-secure the side bracket of the Microwave door panel as the front panel may fall)
7) Remove the 2 screws which held the Microwave unit in place behind the Air Vent Cover on step 6.
8) Wiggle the Microwave unit out about half way to expose the light bulb unit on top center
9) Wiring to the Control Panel will prevent you from pulling the Microwave unit out any further. And you don't want to do that as the unit may fall. Space is cramped, but working carefully with pliers you should be able to release the springs which held down the light bulb unit and change the bulb.

By the way, the bulb is Osram 64405S. It's available online for about $2.00 plus shipping.
See more info. at: http://www.howtomendit.com/answers.php?id=51232

you ll need to pull unit out to replace bulb, 2 scrws remove side trim of oven, 3 or 4 screws remove trim under micro; above oven, 2 more screws behind that grill will release micro from supportthat should free it up enoug to slide foward 6 or 8 inches( the bulb is ontop of the cavity) good luck!