GMC SIERRA 2020 Owner's Manual page 101

100 Seats and Restraints
LATCH anchor weight limits
described at the beginning of
this section, and the following
steps:
Rear Driver Side Position
Rear Driver Side Position
2.1. For a top tether in the
rear driver side position:
2.1.1. Remove the driver
side head restraint
and center
headrest. See
Head Restraint or
Headrest Removal
and Reinstallation
later in this
section.
2.1.2. For first time use,
remove and
discard the rubber
band from the top
tether loop (2).
2.1.3. Route the top
tether (3) through
the loop (2).
2.1.4. Attach the top
tether (3) to the
driver side of the
center top tether
metal anchor (1).