Jack the car up on jack stands. Remove the tires. Remove the nut on the top stud of the shock. Remove the cross bolt in the bottom of the shock. Install a steel washer and rubber cushion on the top stud of the shock. Install the washer with the curve away from the shock. The cushion is installed with the rounded side toward the steel washer. Compress the new shock and fit it into the mounts. New gas shocks come compressed and restrained by a wire. Do not cut the wire until the shock is in its mounts. Install the bottom bolt first, but do not tighten, then allow the shock to extend into the top hole. Install the rubber cushion, the steel washer and the nut on the top stud after it is through the mounting hole. Tighten the nut to compress the cushions to about 2/3 of their original thickness.