How do you replace the brake light on the inside of the car against the back winsheild in a 1991 Chevy Cavalier?
From inside the trunk you will find either access to the bulb or access to the bolts to remove the assembly.
Access to the light is gained underneath it, through the trunk.
I have a 1997 cavalier. If it is the same and I think they are. The best thing to do is go to Wal-mart and get the installation kit. Inside the kit are directions on how to get the old stereo out. Because you have to take the dash off to get to some of the screws. It sounds rough but really it is easy.