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.
Fold down the rear seat to access the rear seatback filler panel retaining nuts.
Remove the rear seatback filler panel retaining nuts.