Buick 2000 Century Owner's Manual page 278

Tail/Stop/Turn Signal Lamp
6-36
1. Remove the plastic wing nuts (A). (Pliers may be
required to remove the wing nuts.)
There is one wing nut located on the outside of
the carpet. The other two are located underneath
the carpet.
2. Pull the taillamp housing (B) away from the body
of the vehicle.
3. Squeeze the tab on the socket and turn the
socket counterclockwise.
4. Pull out the socket.
5. Pull the bulb out of the socket. (There are two bulbs
on each taillamp.)
6. Push in a new bulb.
7. Reverse these steps to reinstall the lamp assembly.