Removal Procedure

Remove the fasteners (1) at the rear edge of the insulators.
Push in on the snap tab retainers in order to release the insulator.

Fig 1: Removing Fasteners & Closeout/Insulator Panel Replacement - Left (RHD)
Courtesy of GENERAL MOTORS CORP.
Disconnect the electrical connectors (1,2) as necessary.
Slide the insulator (3) rearward toward the vehicle.

Fig 2: Disconnecting Electrical Connectors & Insulator Closeout/Insulator Panel Replacement - Left (RHD)
Courtesy of GENERAL MOTORS CORP.