It has been a long time since I did this work, but I'm fairly certain that I was able to pull the front plate by soaking it (I remember soaking the whole engine) in solvent, and then I THINK I held the front plate, and tapped on the crankshaft with a prop nut on it, using a block of wood. The bearings were a press fit so they stayed with the plate. I would NOT pry on the plate if I were you. You want axial force on the crank relative to the bearings so the bearings slip off the shaft and not get cocked.
I never ran the engine. I had it nicely stored for some time, and then all my stuff was lost in a shop fire. That engine, along with a lot of other stuff, was lost in heat, water, dirt and ash. Still disturbed by it - I bought the collector ring for it and was really looking forward to putting it in some lumbering bipe.