To replace one of these bulbs: 1. Open the trunk.
2. Remove the trunk trim and pull back fastener.
3. Remove the additional fastener.
4. Remove the outer two screws from the taillamp assembly.
5. Lift up on the tab and pull the wiring harness straight out.
6. Remove the taillamp assembly from the quarter panel.

A. Sidemarker
B. Stoplamp/Turn Signal/Taillamp
C. Back-up
7. Turn the bulb socket counterclockwise and pull it straight out.
8. Pull the old bulb straight out of the socket.
9. Push the new bulb straight into the socket.
10. Push the new bulb into the taillamp assembly and turn it clockwise to lock it into place.
11. Reinstall the taillamp assembly into the quarter panel.
12. Push the wiring harness straight into the taillamp assembly and push the tab down.
13. Reinstall the outer two screws into the taillamp assembly.
14. Reinstall the trunk trim and the fasteners.
Taillamps and Turn Signal Lamps (Coupe)
Back-Up Lamps (Coupe)Chevrolet Cobalt Service & Repair Manual. Wheel Hub & Bearing, Replace
Rear
Disc Brakes
1.
Raise and support vehicle, then the
tire and wheel assembly.
2.
Without disconnecting the hydraulic
brake flex hose, remove and support rear brake caliper and bracket
as an assembly.
...