Chevrolet 2008 Uplander Owner's Manual page 43

There is one guide for each second row passenger
position. If your vehicle has a third row, there is
one guide for each outboard position. Here is how
to install a comfort guide to the shoulder belt:
2. Place the guide over the belt and insert the
two edges of the belt into the slots of the guide.
1. Remove the guide from its storage pocket on
the side of the seatback.
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