GMC 2004 Yukon XL Owner's Manual page 480

7. Place the bottom edge of the jack on the wheel
blocks, separating them so that the jack is
balanced securely.
5-102
8. Attach the jack handle, extension, and wheel
wrench to the jack and place it (with the wheel
blocks) under the vehicle towards the front of the
rear bumper. Position the center lift point of the jack
under the center of the spare tire.
9. Turn the wrench clockwise to raise the jack until it
lifts the end fitting.
10. Continue raising the jack until the spare tire stops
moving upward and is held firmly in place. The
secondary latch has released and the spare tire is
balancing on the jack.