WARNING: This page is about a different car, the 2003 GMC Sonoma, 2003 GMC Jimmy, 2003 Chevrolet S10 Pickup, and 2003 Chevrolet Blazer. However, it is still accessible from the selected car via links, so may be relevant.
Open the endgate.
Perform the following steps in order to remove the pickup box endgate bumper from the vehicle:
Grip the endgate bumper.
Pull out the endgate bumper in order to release the retainers.