Unscrew the lens on the outside, or take off the plastic cover from inside the trunk, to reveal the bulb. You'll have to push in and turn at the same time. Take the bulb with you to the auto supply store to help you find an exact duplicate. Clean the connection with a wire brush and/or wipe it clean with a rag if there's any corrosion. Screw the new bulb into the empty socket. Again, you'll have to push in and turn simultaneously. Line up the tiny raised bumps on the base of the bulb in order to screw it in. Test your work by stepping on the brakes and turning on the headlights while a friend watches the new bulb to make sure it lights up.
_____________________________________________________________________________ IPCW THIRD BRAKE LIGHT -- With smoked lens; FMVSS-108 compliant;
DOT and SAE approved; A high quality, direct fit OE replacement third brake light.
Using the base of your hand bang down on the top edge of the top light cover. This pushes the cover towards the ground and releases the holds on both sides of the cover. DO NOT TRY TO BREAK FROM THE BOTTOM. Bulb is jammed into a plastic housing that unscrews from the fitting. Reverse to re install.