Kenneth wrote:
....
Getting it off has proven to be pretty tough. Using various
wedging techniques, I managed to get it off for all but
about 1/2" of its length, but I have not had any luck moving
it further than that.

Are you sure you don't have any side torque?

....
I know that by heating the yoke, I should be able to get
some expansion, and that should make removing it a bit
easier, but I have no idea how hot I want it to be to have
benefit, but without damaging the thing.

Also, whatever (approximate) temperature I was to shoot for,
how would I know when I was there?
....

When it starts showing red, move the torch on around.

Do it as quickly as possible to get as little heat transfer to the shaft
as possible. I usually fill it full of WD4O or another (relatively)
non-volatile lubricant first. Seems to help some as it sizzles but
won't start a big flame.

Have the pulling gear all set before start, of course, so doesn't just
cool back down. Good would be if have an extra hand who can apply the
tension or can arrange where you can do it together--then when it begins
to move you don't need to keep on heating...

--