GMC Terrain 2018 Owner's Manual page 73

72 Seats and Restraints
To install:
1. Remove the guide from its
storage pocket on the side of
the seatback.
2. Place the guide over the belt,
and insert the two edges of the
belt into the slots of the guide.
3. Be sure that the belt is not
twisted and it lies flat. The
elastic cord must be behind the
belt with the plastic guide on
the front.
4. Buckle, position, and release
the seat belt as described
previously in this section. Make
sure the shoulder belt crosses
the shoulder. The belt should
be close to, but not contacting,
the neck.
To remove and store the comfort
guide, squeeze the belt edges
together so that the seat belt can be