Chevrolet 2004 Astro Owner's Manual page 296

Rear Position
A. Rear Jack Location
B. Jack
C. Ratchet and Extension
5-82
7. Raise the vehicle by turning the ratchet clockwise.
Make sure the UP mark faces you. Raise the
vehicle far enough off the ground so there is enough
room for the compact spare tire to fit underneath
the wheel well.
8. Remove all the wheel nuts and take off the flat tire.
9. Remove any rust or dirt from the wheel bolts,
mounting surfaces and spare wheel.