WARNING: This page is about a different car, the 2008 Suzuki Swift +, 2008 Pontiac Wave, and 2008 Chevrolet Aveo. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Rear Seat Back Hinge
Courtesy of GENERAL MOTORS CORP.
Lower the rear seat backs.
Remove the bolts that secure the rear seat backs to the hinges.
Remove the rear seat backs by pulling the seat hinge posts out of the front wheelhouse trim.