GMC 2010 Sierra 1500 Crew Cab Owner's Manual page 408

Turn the steering wheel left and right to clear the
area around the front wheels. For four-wheel-drive
vehicles, shift into Four Wheel High. For vehicles with
®
StabiliTrak , turn the traction control part of the system
off. Shift back and forth between R (Reverse) and a
forward gear, spinning the wheels as little as possible.
To prevent transmission wear, wait until the wheels stop
spinning before shifting gears. Release the accelerator
pedal while shifting, and press lightly on the accelerator
pedal when the transmission is in gear. Slowly spinning
the wheels in the forward and reverse directions causes
a rocking motion that could free the vehicle. If that does
not get the vehicle out after a few tries, it might need to
be towed out. Recovery hooks can be used, if the
vehicle has them. If the vehicle does need to be towed
out, see
5-32
These hooks, when used, are under a lot of force.
Always pull the vehicle straight out. Never pull on
the hooks at a sideways angle. The hooks could
break off and you or others could be injured from
the chain or cable snapping back.
.