GMC 2003 Safari Owner's Manual page 11

Reclining Seatbacks
There is a lever located on the inside of the seat to
adjust the seatback.
You can adjust the
seatback by lifting the
lever and leaning back.
Release the lever to
lock the seatback where
you want it. Pull up on the
lever, lean forward and
the seatback will go to an
upright position.
But don't have a seatback reclined if your vehicle
is moving.
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