2. Very carefully inspect the sealing surface of the crankshaft for scratches that could damage the edge of the new seal and cause oil leakage. If the crankshaft is damaged, it must be replaced.
3. The old seal can be removed from the cover from the back using a hammer and a mandrel (see illustration). Before removing the seal, note how deep it is recessed into the hole; the new seal should be recessed to the same depth. Be careful not to scratch or otherwise damage the wall of the hole in the holder to avoid oil leakage.
24.3 Place the holder on two wooden blocks and remove the cuff using a mandrel or a screwdriver and hammer
4. Check the cover for cleanliness, then lubricate the outer edge of the new seal with engine oil. The seal must be inserted into the hole without slanting, so it is not recommended to use a hammer. If you do not have access to a press, clamp the housing and seal between two smooth wooden blocks and press the seal into place using a clamp or large vice. The wooden blocks should be thick enough to distribute the force evenly around the seal. Work slowly and install the seal without slanting.
5. As a last resort, the cuff can be pressed into the lid with a hammer. To distribute the force evenly, use a wooden block and install the cuff without skewing.
(The article is reprinted from a web resource: mitsubishiman)
6. Before installing the cover with the seal on the crankshaft and screwing it to the block, the edges of the seal should be lubricated with clean engine oil or molybdenum-based grease. Use a new gasket.
7. Tighten the bolts evenly to the required torque.
8. If the engine is equipped with an oil separator, install it with the oil channel towards the bottom of the oil seal holder.