GM Service Manual Online
For 1990-2009 cars only

To replace the center high-mounted stoplamp (CHMSL) bulb, do the following:

  1. Open the liftgate. See Liftgate for more information.
  2. Remove the two screws and then the cover.

  3. Object Number: 1054329  Size: A3
  4. Depress the bulb and rotate it counterclockwise to remove it from the bulb socket.
  5. Replace the bulb with a new one.
  6. Reverse Steps 2 and 3 to reinstall the assembly.