Before you get started on this, do clean the engine to confirm it's that seal, then, get ALL the parts & tools that you'll need, and finally, get a copy of the procedures you plan to use & visually plan it all out. When you change the seal, use the proper removal/installation tool & be careful not to scratch the surface of the crank where the seal rubs, and before installing the new seal, inspect that area of the crank to see if it's completely smooth - sometimes the seals fail because their quality is crappy, sometimes they leak because there's a groove worn into that area of the crank allowing the oil to creep by. If you find that the crank surface for the seal is either worn or defective, you can repair this without removing the crank. You can use what's called a micro-sleeve and an oversized seal. The micro-sleeve is a very thin and hard sleeve that slides over the crank seal area and is bonded to the crank. The oversize seal then goes over this sleeve & holds in the oil.