Damn plumbing. Never did fancy it.

Replacing 3 handle faucet setup in a shower. Actually got a specific kit
made aware of in this NG.. All new handles, flanges, stems, seats, the
works for $35 called a remodel kit. Got stems and seats out of both hot
and cold OK. The diverter won't budge. Got pretty good wrench on it. Did
some muscle, some tapping (praying sweat joints behind wall don't give),
soaked with product like Liquid Wrench for several hrs. NG.

Only thing I can think of now is heating it. keeping in mind to open the
valve so that the seat washer doesn't melt down into the supply pipe and
that there's a plastic washer on the diverter.

Stem is long which limits some options.

I scribbled a blue arrow on this pic. That's where I'm thinking of
heating it.

http://tinypic.com/view.php?pic=r0t4aw&s=3

Looking close, it looks like there's some goop where the stem base meets
the wall pipe where it should separate. If it's the same goop that looks
like is in the bonnet, that's soft goop. The bonnet does come off easily.

Ideas & Suggestions?