GMC 2000 Safari Owner's Manual page 243

Put the flat end of the extension on an angle through the
hole in the rear door frame, above the bumper. Be sure
the flat end connects into the hoist shaft.
Turn the ratchet counterclockwise to lower the spare tire
to the ground. Keep turning the ratchet until the spare
tire can be pulled out from under the vehicle.
5-22
Pull the tire out from under the vehicle.
NOTICE:
To help avoid vehicle damage, do not drive the
vehicle before cable is restored.
When the tire has been
lowered, tilt the retainer
plate at the end of the cable
and pull it through the
wheel opening.