GMC 1996 Sierra Owner's Manual page 55

You'll be using the lap-shoulder belt. See the earlier part
about the top strap if the child restraint has one.
1. Put the restraint on the seat. Follow the instructions
for the child restraint.
2. Secure the child in the child restraint as the
instructions say.
3. Pick up the latch plate, and run the lap and shoulder
portions of the vehicle's safety belt through or
around the restraint. The child restraint instructions
will show you how.
If the shoulder belt goes in front of the child's face or
neck, put it behind the child restraint.
4. Buckle the belt. Make sure the release button is
positioned so you would be able
t o
unbuckle the
safety belt quickly if you ever had to.
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