Take the crankshaft damper/pulley off the engine. So very carefully, use a seal removal tool or a large screwdriver to pry the seal out of the cover, but be careful not to nick the cover. Do not scratch, gouge, or contort the place where the seal fits since that will cause oil to leak. Wipe the bore of all old seal material and corrosion and fit the new seal in the bore with the seal lip inward facing towards the engine. A little oil applied to the outer rim of the new seal will help in installation. Press the seal into the bore with a seal driver or big socket and hammer until the new seal is firmly pressed in place against the cover flange. Coat the lips of the seal with engine oil and fit the crankshaft pulley again. The rest of the installation is in the opposite order of the removal. Once the installation is made, ensure that the engine is started and you shouldn't see any oil leakage.