GMC Safari 2003 Owner's Manual page 14

5. Lift up on the left and the right seat release levers
at the same time. The latches are near the floor on
the rear legs of the seat.
1-8
6. Lift up on the rear of the seat to remove the seat
assembly from the rear latch pins. Then, pull back
and lift the seat out of the vehicle.
Your seat release latch lever is operated with a
two-stage mechanism. To fully release the latch, two
levels of lift effort will be required. First, a low
effort to overcome the first stage and then a
moderate effort to fully release the latch.