I'm new to the site, but thought I would post a simple tool I built in about 10 minutes time (assuming you have a welder.)

It is just a fat washer with a large nut welded to it. Three small holes drilled in the washer to line up with the three threaded holes in the flywheel. Thread three bolts into the flywheel, then thread a bolt through the big center nut up against the snout of the crank. I used a Subaru strut-to-hub bolt/nut, since I had a bunch of spares. But a common 1/2-13 UNC bolt would work just as well.
I found it required very little tightening of the center nut to make the flywheel pop off, and this was on a fairly rusty engine. I just used a medium size flat blade screwdriver between two of the small bolts to keep everything from spinning. Minimal muscle was required.
Hope this helps someone.
Chris H.