1987 Chevy Celebrity bulb replacement

Rear Turn Signal, Brake and Parking Lights

Remove the tail light assembly screws, then the assembly.
Disconnect the twist lock socket from the lens housing.

To remove the bulb, turn the twist lock socket (at the rear of the housing) counterclockwise1/4turn, then remove the socket with the bulb; replace the bulb if defective.

To install:

Attach the socket assemblies to the back of the lamp unit.
Install the lamp assembly to the vehicle with the mounting screws.