GMC 2005 Canyon Owner's Manual page 16

Rear Seat Operation (Extended Cab)
To fold the rear seat down, pull down on the bottom of
the seat until the seat is in place.
The rear seat storage compartments must be in the
rearward position before folding the seat down.
1-10
If your vehicle has an
extended cab, there may
be a forward folding seat in
the rear area.
To store the seat, do the following:
1. To ensure that the safety belt buckle does not
move when not in use, secure it to the inboard
side of the seat by the hook and loop fastener (A).
2. Push the entire seat up until it is flush with
the trim panel.