I dont know if any one has done this post before but I just finished doing my main crank oil seal "causing me to burn oil bad and smoke horrendously" I just removed the case then the flywheel .. and let me tell you, It is a must to have a flywheel remover. I also did the nylon rope in the head trick.. "if you dont know what this is you roll your motor over till half way to tdc "aka" as soon as your piston clears the exhaust on the motor, cant see enless your head pipe is off" then follow that up by inserting about 3 feet of rope thought the spark plug hole once this is done u can  get the fly wheel bolt off without using a Impact gun. once that is done insert the flywheel tool into the fly wheel about 10 turns then proceed to turn down the top bolt till it works off the flywheel then put a screw into the oil seal then pull out the old oil seal .. then clean the crank and surroundings out with carb cleaner then I used blue loc tight and insert the new seal then push it down with a 2 inch pvc pipe to a bit lower then flush..  let it dry for at least 24 hrs tighten every back down and then your good to go if u need to ask questions please do or if i made any errors correct me please

 

Sounds like you knew what you were doing!