2008 Hummer H3 Owner's Manual - Page 344

6. Turn the wheel wrench clockwise to raise the jack head to the lifting point. {CAUTION: Getting under a vehicle when it is jacked up is dangerous. If the vehicle slips off the jack, you could be badly injured or killed. Never get under a vehicle when it is supported only by a jack. {CAUTION: Rear Tire Flat: You will need to use the jack handle and both jack handle extensions. Attach the wheel wrench to the jack extensions. Attach the jack handle to the jack. From the rear of the vehicle align the jack under the rear axle. Turn the wheel wrench clockwise to raise the vehicle. Raise the vehicle far enough off the ground so there is enough room for the spare tire to clear the ground. Raising your vehicle with the jack improperly positioned can damage the vehicle and even make the vehicle fall. To help avoid personal injury and vehicle damage, be sure to fit the jack lift head into the proper location before raising the vehicle. 5-86