First of all, to replace the front Crankshaft Seal with the timing chain cover in place, remove the fan shroud, fan/clutch assembly, and drive belts. Extract the crankshaft bolt, and use a puller to detach the vibration damper. Care should be taken not to damage the cover or seal bore as you remove it using a special tool or a chisel and hammer. Inspect for any damage. Use a special tool or a socket and hammer to install the new seal. For engines with the timing chain cover removed, drive out the seal, clean the bore, and install the new seal with a socket and hammer. The procedure for rear main oil seals differs depending on whether one-piece or two-piece seals are used. To replace a one-piece seal, you need to take out the transmission, drive plate, and rear cover plate first. Remove this old one by prying off carefully then clean up back in there before applying both oil and grease on a new one that is pressed in place.