Inside trunk, remove thumb screw to fold back paneling near tail lights. Then remove three thumbscrews and the whole tail light assembly can be moved out to change light bulbs.
You can access the Nissan taillights from the cargo compartment. Remove the tail light assembly cover. Remove the tail light wiring harness. Remove the tail light assembly retaining bolts.
If you can't get to the back of the light through the trunk, you have to remove the light to change the bulb from the rear.
Open the tail gate...you need to remove 2 screws that hold the tail light cover. The cover is also held in place by a couple of snap on fasterners so you need to pull the cover outward to take it off.
In trunk remove thumb screw, bend back paneling, remove 3 thumb screws and pull out whole tail light fixture. Now you can replace bulb(s).
To change the brake light bulb in a 2003 Alero, first, open the trunk and locate the tail light assembly. Remove the screws or clips securing the tail light, then gently pull the assembly out. Twist the bulb socket counterclockwise to remove it, replace the old bulb with a new one, and reassemble by reversing the steps. Ensure the new bulb is securely in place before closing the tail light assembly.
Open the trunk and remove the nuts holding the assembly in place. With nuts removed the tail light assembly will come out the back then you can remove the light socket to replace the bulb.
Open the trunk, above the tail light there is a black cover. Remove the cover. The tail light slides off away from the car.
the cover does not come off, you must remove the entire light assembly and remove the bulb from the back side
The cover does not come off. The tail light is an assembly, that is removed as one piece. The fasteners are accessed from in the trunk.
there is a plastic cover above the tail light held on by two screws. remove that and simply pull the tail light out.
Open tail gate, remove the two small screws going in from the side, wiggle tail light housing straight back and out.
The short answer is you don't. The entire unit is serviced as a unit, individual parts are not available new.