I just replaced the rear air suspension on a 99 Lincoln.
Remove the rear tires and look in the area between the frame and the bottom of the trunk and you’ll see the nuts for the top of the shocks. These aren’t easy to get to so the best way to remove them is to cut the shafts of the shocks from under the vehicle with an oxy/acetylene torch.
To install the bushing. washer, and nut onto the new shock, take a metal rod with a sharp point and poke it into the bushing. Reach in and place the bushing onto the shock shaft. With a telescoping magnet place the washer on top of the bushing. With the magnet place the nut on the shock shaft. Reach in and spin the nut down by fingers. Using a ratcheting box wrench tighten the nut.
Tester