GMC 2007 Yukon XL Owner's Manual page 510

2. Remove the wing nut (B) used to retain the
tool bag by turning it counterclockwise.
3. Turn the knob (A) on the jack
counterclockwise to release the jack and
wheel blocks from the bracket.
4. Remove the wheel blocks and the wheel
block retainer by turning the wing nut (C)
counterclockwise.
510
The tools you will be using include the following:
A. Jack
B. Wheel Blocks
C. Jack Handle
D. Jack Handle
Extensions
E. Wheel Wrench