A: To replace the upper balljoint, start by loosening the wheel lug nuts and raising the vehicle on jackstands. Remove the wheel and place a jack or jack stand under the lower Control Arm. Remove the cotter pin and back off the nut on the balljoint stud. Use a special tool or a fabricated equivalent to press the balljoint out of the Steering Knuckle. Drill holes in the rivet heads and use a drill bit to remove them. Knock out the rivet shanks and remove the old balljoint from the control arm. Position the new balljoint on the control arm and install the bolts and nuts provided. Tighten them to the specified torque. Insert the balljoint stud into the steering knuckle and tighten the nut. Install a new cotter pin and the bracket for the wheel speed sensor harness if necessary. Install the balljoint grease fitting and fill the joint with grease. Finally, install the wheel and drive the vehicle to an alignment shop for a front-end alignment check and adjustment if needed. For the lower balljoint, the process is different as it requires special tools. The lower control arm needs to be removed and the old balljoint pressed out and the new one pressed in.