Unscrew the rear wheel bolts and then elevate the rear of the car and place it safely on jackstands then remove the wheel. Loose the brake caliper, including the hose, but not the component of the mounting bracket and disc, or the brake drum. In models that have rear disc brakes, suspend the caliper using a strip of wire to prevent tension on the brake hose. With a hammer and a big chisel, tap and pry out the cap in the centre of the brake disc, substitute it with a new disc should it be distorted. You will need to loosen the cotter pin of the hub nut, the nut lock, and lose the cotter pin, and a replacement one must be obtained when reassembling. Take the place of the rear hub nut, push the washer off, and the outer bearing, then the disc can be slipped down the stub axle. Lift the grease seal off the hub without scratching the rotor of the ABS wheel speed sensor and remove the inner bearing. Evacuate the races with an appropriate soft metal drift without any harm to the rotor of the hub and ABS speed sensor, and only evict them when changing the bearings. Clean the bearer race points in the hub and insert a bushing or bearing driver pushing the new races into place making sure that they fit into the location squarely and fully. Apply grease to the bearings, fit in the inner bearing and stuff the gap between the seal lip and the casing with grease and then grease the seal into place by pushing it into place. Grease the seal lip with grease, put additional grease on the center of the hub and then fit it on the stub axle and then the outer bearing, thrust washer and hub retaining nut. Turn the hub and screw the hub nut in slowly to about 15 ft-lbs to create the bearings correctly seated, and then loosen the nut until it becomes just loose and then secure it by hand. Install the washer, ensuring that a screwdriver can ensure the washer is moved to one side, screwdriver, add a nut lock, and add a new cotter pin, and take care not to install the nut too tightly, since it will wear out the bearing prematurely. Apply the grease into the dust cap and push it into place then position the brake caliper and then attach the wheel and the bolts, pushing the vehicle down and tying the bolts to the required torque. Play should be checked after several hundred miles (unless a new bearing has been installed in which case re-checking may be needed). In models of VW Passat that have sealed bearings, loosen the hub-to-rear axle bolts using the holes in the hub flange, strip the bearing assembly off the axle, and loosen any attached stubbornly by striking it sideways. Installation is the opposite of removal, where the area of hub-to-axle mating surfaces should be clean, and the mounting bolts should be tightened to the required amount and the caliper and wheel bolts attached and then the vehicle should be lowered and the bolts attached. In all-wheel drive models, some special tools and skills are needed and, as such, this task ought to be assigned to a qualified mechanic, though the rear knuckle and hub can be removed and brought to an appropriate repair shop.