GMC Express 2011 Owner's Manual page 114

3-66 Seats and Restraints
You will be using the lap-shoulder
belt to secure the child restraint in
this position. Follow the instructions
that came with the child restraint.
1. Move the seat as far back as
it will go before securing the
forward-facing child restraint.
If you have no other choice but
to install a rear-facing child
restraint in this seat, make sure
the airbag is off once the child
restraint has been installed.
When the airbag off switch
has turned off the right front
passenger frontal airbag, the off
indicator in the airbag off light
should light and stay lit when the
vehicle is started. See Airbag
On-Off Light on page 5 18.
2. Put the child restraint on
the seat.
3. Pick up the latch plate, and
run the lap and shoulder
portions of the vehicle safety belt
through or around the restraint.
The child restraint instructions
will show you how.
4. Push the latch plate into the
buckle until it clicks.
Position the release button on
the buckle so that the safety belt
could be quickly unbuckled
if necessary.
5. Pull the shoulder belt all the way
out of the retractor to set the
lock. When the retractor lock is
set, the belt can be tightened but
not pulled out of the retractor.