Lift the vehicle and secure on jackstands. Set transaxle in Neutral, parking brake off, remove driveshaft. Measure pinion flange's turning torque with an inch-pound torque wrench. Remove the retaining nut and pinion flange, using suitable tools. Remove old seal, install new one with a large socket, ensuring it's square to the bore. Gradually tighten pinion flange retaining nut, checking the turning torque periodically. Once the original torque is reached, tighten the nut to increase torque by five inch-pounds. Reinstall driveshaft and lower vehicle.