Can't be done with a case in key unless you want to cut the cast key off and figure out where the flywheel goes when you put it back on...Put some Loctite on the taper and bolt the flywheel on tight with the new hub or a nut.....When the loctite is set up take the hub or nut back off..the flywheel will stay on the shaft..Bolt the engine upright in a mill and carefull machine the face of the flywheel where the hub seats, slowly turning the flywheel by hand.....be sure the engine is held tightly, and go slow..Makes a perfect 90 degree face to the crank, and if the hub has parallel faces there will be no prop tip runout...