The rear Crankshaft Seal is relatively easy to replace as one does not even have to remove the oil pan or the crankshaft. Starting with, the transmission must be pulled out and in case of the manual transmission then detach the pressure plate and the clutch disc as well. Third, pull off the flywheel or, if your car has one, the driveplate will have to do. Using a seal removal tool or a large screwdriver gently push the seal out of the block without damaging the crankshaft since this damages the new seal and it leaks. Assist in 'degapping' the bore in the block and the seal contact surface on the crankshaft; look for any sharp edge that can damage the new seal lip and cause oil leakage; if the crankshaft is badly worn, then a new or different crankshaft will be needed. Dip the outer rim of the seal in a thin coat of engine oil or multi-purpose grease and coat the lip of the seal with moly-base grease. Place the new seal into the hole and use a tool that can be bought in auto part stores, to press the seal in or down with lip facing forward of the engine. If the special tool is not possible to use, then gently slide the seal lip over the end of the crankshaft then strike the seal with a hammer and punch until it is flushed into the bore. Then re-install the flywheel or drive plate and the clutch disc and pressure plate if the car is fitted with a manual transmission and then put the transmission back into position.