Hummer 2006 H2 Owner's Manual page 420

Jack B (SUV and SUT)
2. Attach the wheel wrench to the extender.
5-90
1. To remove the center
cap, place the flat end
of the wheel wrench
in the slot on the wheel
and carefully pry the
center cap out.
3. Turn the wheel wrench counterclockwise to loosen
the wheel nuts. Do not remove them yet.
You will now need to jack the vehicle up using the
following instructions.