Hummer 2005 H2 Owner's Manual page 384

4. Open the tool bag and you will find the following
tools which you will use to remove the spare tire
and flat tire:
A. Jack Handle
B. Jack Handle
Extension (Used
for Rear
Flats Only)
5-72
C. Wheel Wrench
D. Ratchet
E. Spanner Wrench
SUT
The equipment you'll need is the rear cargo
compartment on the passenger's side of the vehicle.
Unlock the cover and pull it off.