Loosen the rear wheel lug nuts, raise the rear of the vehicle and support it securely on jackstands. Block the front wheels to keep the vehicle from rolling off the stands. Remove the rear wheels. Position a jack under the rear axle differential case. Disconnect the driveshaft from the rear axle companion flange. Fasten the driveshaft out of the way with a piece of wire from the underbody. Disconnect the shock absorbers at the lower mounts, then compress them to get them out of the way. If equipped, disconnect the vent hose from the fitting on the axle housing and fasten it out of the way. Disconnect the brake hose from the junction block on the axle housing, then plug the hose to prevent fluid leakage. Remove the brake drums. Disconnect the parking brake cables from the actuating levers and the backing plate. Disconnect the spring U-bolts. Remove the spacers and clamp plates. Lower the jack under the differential, then remove the rear axle assembly from under the vehicle. Installation is the reverse of removal. Lower the vehicle weight onto the wheels before tightening the U-bolt nuts completely. Bleed the brakes.