[fred cook]

Because of the amount of labor involved, I would buy or borrow a seal installation tool to make certain the seal gets installed correctly. Also, when you get the old seal out, check the crankshaft to see if there is a wear ring. If so, try to insert the new seal so that it wears on a different spot. A tiny bit of wear can make a huge difference. Also, best do the work now before the oil gets onto the clutch friction surface!