2004 GMC Yukon 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. 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. 5-102