My 89 rs is equipped with map reading lights on the rearview mirror. One of them is not working, burned out bulb i think. The other one is falty in the sense that it only turn off if the switch is balanced between on and off. Any ideas how to fix this? How do I replace the bulb? I can't seem to figure out how to open the system to get at those bulbs.

 

There's a tiny slot on one edge of the lens. You just carefully pry it out with the tip of something like a fingernail clipper.