GMC 2011 Yukon XL Denali Owner's Manual page 84

3-28 Seats and Restraints
Second Row
Here is how to install a comfort
guide to the safety belt:
1. For the second row, remove the
guide from its storage clip on the
interior body.
Third Row
If your vehicle has a third row,
remove the guide from its
storage pocket on the side of
the seat.
2. Place the guide over the belt,
and insert the two edges of the
belt into the slots of the guide.