GMC Sierra 2018 Owner's Manual page 106

2.1. Find the lower anchors
for the desired seating
position.
2.2. Put the child restraint on
the seat.
2.3. Attach and tighten the
lower attachments on the
child restraint to the lower
anchors.
3. For forward-facing child
restraints, attach and tighten
the top tether to the top tether
anchor (loop). Follow the child
restraint instructions, the
vehicle LATCH anchor weight
limits described at the
beginning of this section, and
the following steps:
Example Rear Driver Side
Position
Seats and Restraints
Example Rear Driver Side
Position
3.1. For a top tether in the
rear driver side position:
3.1.1. Remove the
headrest.
3.1.2. Route the top
tether (4) through
the loop (3) on the
driver side under
the center
shoulder belt (2).
3.1.3. Then attach the
top tether (4) to
the top tether
105