1. Using a screwdriver, remove the trim from the brake light assembly.
2. Turn the bulb socket counterclockwise and remove it from the lens.
3. Pull the bulb out of the socket.
4. Make sure that there is no corrosion of the cartridge and insert a new lamp into it.
5. Install the bulb socket into the lens. Turn the cartridge clockwise to fix it in the lens.
6. Place a trim strip on the assembly base. Screw in and securely tighten the mounting screw.