WARNING: This page is about a different car, the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
Open the liftgate.
Using a grease pencil, mark the position of the liftgate striker to the body.
Remove the bolts that retain the liftgate striker to the body.