When you are removing the flywheel, break the center bolt loose but only unscrew it maybe 1/8". Put a good puller on pushing against the bolt head. This will keep the flywheel from flying off when it lets loose. Then tighten the puller up tight. If it hasn't let loose smack the puller on the center bolt with a big hammer. Give it a good smack. It should pop loose. If not try tightening up more and give another smack.
Good luck
Jim