GMC Canyon 2016 Owner's Manual page 85

84 Seats and Restraints
seat cushion extension for
booster seats that extend past
the front edge of the seat
cushion.
2. Press the button for the
passenger side headrest at the
top of the seatback and pull up.
3. Insert the headrest posts into
the holes on the front of the
passenger side seat cushion to
install the seat cushion
extension. The notch on the
posts should face the
passenger side of the vehicle.
Try to move the headrest to
make sure it is locked in place.
4. If the child restraint
manufacturer recommends that
the top tether be attached,
adjust the top tether to its full
length and attach the top tether
hook to the anchor. Refer to
the child restraint instructions
and the following:
Route the top tether (1) through
the loop (2) at the top of the
seatback directly behind the
child restraint and attach the
top tether hook to the top tether
loop at the top of the seatback
for the opposite rear seating
position (3).