Try Marvel Mystery Oil. You can get a pint at any Walmart for about $1.50. It will loosen up any gum or sludge, and provide protection and lubrication.

Usually you must remove the cylinder sleeve to get the con rod off. Removing the sleeve often gives you just enough room to pop it off the crank pin. The rod must slide freely back and forth on the piston pin as well, so that may be another place to look that could be frozen up. Once you get the con rod off and the piston out, a little tapping with a piece of wood on the tip of the shaft will get the crank out. Lay the case on the back plate surface (with the back plate off, of course), get a little piece of wood to hold onto the tip of the crank, and tap it lightly with a hammer. The crank should fall out.

To remove the bearings, heat the case (with all other parts removed) in an oven - just 250 degrees or lower, and use a wooden dowel at a slight angle and a tap with a small tack hammer. You'll find you can place part of the dowel on one of the races - enough to give it a soft tap with the hammer. The goal is not to damage the case or the bearings when you do it!