Installation Procedure

WARNING: This page is about a different car, the 2003 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.

Install the high-mounted stoplamp sockets to the high-mounted stoplamp assembly, then rotate the sockets clockwise to secure.
Install the high-mounted stoplamp assembly locating tabs (2) into the slots on the rear shelf panel.
Slide the high-mounted stoplamp assembly toward the rear of the vehicle to secure the retaining tabs (1).
Install the rear window trim panel. Refer to TRIM PANEL REPLACEMENT - REAR WINDOW SHELF in Interior Trim.

Fig 1: Installing High Mounted Stop Lamp
Courtesy of GENERAL MOTORS CORP.