To lift the 2002 and older Expedition and Navigator models with air suspension, press the air suspension off button in its panel on the right side. First, loosen the wheel lug nuts in the back, lift the whole car using jackstands, and hold its back firmly so it doesn't roll. Keep the front wheels from moving by blocking them. While keeping the rear wheels loose, lift the car and stabilize the rear axle where the gears meet (differential) with a jack holding up the floor underneath. You have to take off both the frame and the axle bolts to get a suspension arm out. Putting the air suspension system back into service is similar to taking it apart, so if your car has an air suspension, you need to reactivate it afterward.