My alternative, providing the other crank and cup can come off: Remove opposite cranks Cup, and lockring if applicable
Install bolt or nut on bb axle fully. Back off 2 turns.
Support frame horizontally (bb axle vertical) with heavy pipe under bb shell. Pipe can rest on tabletob or ground. Heavy and very 'sinky' and 'dead' are the key.
Wail on the nut or bolt with a heavy wallop. Use a drift, hammer, but be square (and obey the laws of the pack!) and follow through. If the not or bolt bottoms, loosen a turn or two more, and whack it again.
Sooner or later, the bolt or not get removed and the axle falls through to China, unless you are there, in which case it comes to North America.
A blow to the axle itself will get it out, but there's a chance the threads and/or profile of that axle might deform.
Larry 'get a bigger hammer, if not, swing harder' Black