How to replace light bulb in Whirlpool GMC275PDQ2 microwave?

I called Whirlpool customer support and ordered the replacement bulb (part #4375348) $24 + $6 shipping. I thought this would be a simple little "honey-do" project, but it's anything but. Our unit is built into the wall and there's no way to get behind the unit. We started by removing the 2 side trims along the oven/microwave. We then removed the black plastic grill just above the microwave door. Then we were able to lift up the control panel above the microwave. This exposed a lot of wires, but the bulb is not exposed. The bulb is below a metal sheet which leads into the vent area (I believe). At this point we couldn't figure out how to get below the metal sheet into the vent area because some of the screws are in places where we can't get a screwdriver in. It seemed the only way was to dismantle the entire microwave/oven, and we thought better not to. We put everything back together again, and were glad everything still worked (except the light).

I don't want to spend $$$ to have a service person come out to change a light bulb. We could live w/o a microwave light, but thought I would post a question out here in case someone has success with replacing the microwave light and have words of wisdom for us.