Before it is possible to replace the front seal with the engine front cover in place it is required to drain the cooling system and remove the drivebelts, the radiator and the crankshaft drivebelt pulley. Apply a slide hammer and a seal puller to make the removal of the old seal easy; check the seal bore, crankshaft, and the surface, which the seal comes into contact with, for nicks or burrs. Place the new seal into the bore with the open end of it facing inside; it is advisable to coat the outer diameter of the seal with a small amount of oil. Gently force the seal down into the bore and it should just sit against the front cover if special tools are not available, use hammer and socket of the same size. Install the crankshaft pulley with the bolt tightened again and make the rest of the installation in the reverse manner and start the engine and check for leakage. If the front cover is removed the support it on wooden blocks and by means of a punch and hammer, knock out the seal and examine the seal bore for nicks or burrs. The lip of the new seal should be placed towards the inner part and a thin layer of clean engine oil spread on the outer circumference after which it is hammered into position using a seal driver or socket /piece of pipe. Tranmission and clutch if it is provided should be first removed next is the flywheel then followed by the engine rear plate so as to access the rear seal. The main bearings cap is removed and two holes are punched above these caps on the seal It is then pulled out with the help of large scredrivers or small pry bars but care should be taken not to scratch the crankshaft seal surface where the seal has been removed. Remove the oil seal and clean the oil seal bore and crankshaft sealing surface, apply a thin layer of clean engine oil to the outer diameter of the new oil seal and then can insert the new oil seal such that the open end is towards the inside. Tighten the seal up to a specific depth with a seal driver or a socket/piece of pipe as the case maybe.