Remove fan cover, leaving pull start attached
Remove Flywheel nut
Thread the 6mm puller bolt into one of the threaded holes in the flywheel
Tighten bolt against case behind flywheel (look for high spot on case) until flywheel pops off
Remove stock woodruff key from crankshaft
Wipe end of crankshaft clean
Apply a small amount of grease to crankshaft end and keyway
Install the Advance key with the offset on the right side (towards rear of scooter)
Re-install flywheel, lining up the keyway in the flywheel with the advance key.
Press flywheel on as far as possible by hand, it may be tight going on to the Advance Key
Install flywheel nut and tighten
Re-install fan cover
Re-check flywheel nut after first 5 minutes of use

*Note: Advance key replaces the stock woodruff key.