2005 GMC Sierra 1500 Pickup Owner's Manual - Page 459

7. Put the bulb socket back into the turn signal housing and turn it clockwise until it locks. 8. Put the turn signal housing back into the vehicle placing the hook and posts on the inner side into the alignment holes first, then the outer side into the retainer bracket until you hear a click. 9. Put the headlamp assembly back into the vehicle. Roof Marker Lamps To replace a roof marker lamp bulb, do the following: 1. Remove the two screws and lift off the lens. 2. Press the retainer clip (B), located behind the turn signal housing, towards the outside of the vehicle. 3. Pull the turn signal housing out of the vehicle. 4. Press the locking release lever, turn the bulb socket counterclockwise and remove it from the turn signal housing. 5. Remove the old bulb from the bulb socket. 6. Put a new bulb into the bulb socket. Use care not to touch the bulb with your fingers or hands. 5-65