how to repair my rear signal light

look in trunk, behind light,pull felt away see if light sockets are their to turn and pull out of hole for bulb change.pull the correct bulb

if no acess to sockets then bolts must be removed to pull plastic taillight off and unplug sockets

On most G.M. cars, you have to pull the light assembly. Open the trunk. On each side of the opening, you will see some large, black plastic butterfly nuts. There are normally 3 per side, but that does vary. Undo all of them on the affected side, and pull the light assemble straight out from the body of the car. Squeeze the tab on the socket and turn it about 1'4 turn counterclockwise, and the socket will lift out of the housing. If,as I suspect, your car used the 3051/3151bult, it pulls straight out of the socket. If it takes a1057/1157 bulb, push down on the bulb and turn 1/4 turn counterclockwise and pull it out. Installation is the revers.

you got it michael