GMC SIERRA 2002 Manual page 76

To remove the child restraint, just unbuckle the vehicle's
safety belt and let it go back all the way. The safety belt
will move freely again and be ready to work for an adult
or larger child passenger.
-
If you were using a rear facing child restraint in a
regular cab pickup or an extended cab pickup, turn on
the right front passenger's air bag when you remove the
-
rear facing child restraint from the vehicle unless the
person who will be sitting there is a member of a
passenger air bag risk group. See "Air Bag Off Switch"
in the Index.
CAUTION:
If the right front passenger's air bag is turned off
for a person who isn't in a risk group identified
by the national government, that person won't
have the extra protection of an air bag. In a
crash, the air bag wouldn't be able to inflate and
help protect the person sitting there. Don't turn
off the passenger's air bag unless the person
sitting there is in a risk group. See "Air Bag Off
Switch" in the Index for more on this, including
important safety information.
1-69