The alternator rotor does not need to come off of the crank for engine rebuilding. It must be removed for crank balancing. It is on a taper and a simple threaded puller is used to remove it, in theory. A puller was threaded in and I zapped it with the impact gun. No progress. Then I zapped it again and the threads stripped on the puller. The puller was shortened on the lathe so it had good threads. Then I threaded it in again and tightened it up with the impact gun. Then I applied heat to the female part on the taper. The rotor would not pop loose. I was successful at melting the electricity generating innards. Another sacrifice to the speed gods. Now I drilled a bunch of holes in it and took off the outer part. Then some slots were made to weaken the part. I applied more heat, some cussing, more cursing in German, and nothing happened. This morning it went to the machine shop. They put it in their ginormous press and popped it off.
The machinist explained what happened. They probably put a warm rotor on a cooler crankshaft in Hinckley. The rotor cooled and it contracted down onto the taper. The fit was very tight and it conducted heat really well. I applied heat, both the rotor and the shaft got hot at the same time, and they expanded together. That is why heat would not work and the taper fit was so strong.
My advice is to not do what I did. First, try the puller. Take the crankshaft into a machinist to be pressed off if this does not work. This will preserve the rotor.