GMC Hummer H3 2008 Owner's Handbook Manual page 317

Problems on the Road
5. Turn the wheel wrench clock-
wise to raise the jack.
Raise the jack until the jack
head fits firmly into place.
. . . 316
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.
No person should place any
portion of their body under a
vehicle when it is supported
only by a jack.
CAUTION
Raising your vehicle with the
jack improperly positioned can
damage the vehicle or may
allow the vehicle to fall off the
jack. To avoid personal injury
and vehicle damage, be sure to
fit the jack lift head into the
proper location before raising
the vehicle.
6. Raise the vehicle off the
ground until there is room for
the spare tyre to fit.