Open the trunk of the car.
Locate the brake light assembly, which is on the side of the car where the bulb is out.
Remove the two screws that hold the brake light assembly in place.
Pull the brake light assembly out of the car.
Remove the old bulb by turning it counterclockwise.
Insert the new bulb by turning it clockwise.
Replace the brake light assembly and the screws.
Test the brake light to make sure it is working properly.