Well Jesus Christ.....
I froze the thing for 3 more hours and the epoxy STILL didn't budge.
Impossible to twist off, unless you're superman.
I then tried to chisel it off with a (bare) razor blade, but that didn't work. All it did (and with a very mildly cut finger to boot) was let me see the very edge of the epoxy.
And I couldn't use the blade holder since it would probably rip off resistors.
And all of this is with carefully trying to avoid ripping any small parts off the card.
So then I decided....well I might as well attempt to pry it off with a knife again, while the card was still frozen, and hopefully, not crack anything.
So I pried..and pried.and pried....
then after a really huge pry........ Klunk......the heatsink pops off.
JESUS F**** CHRIST.....
This thing was probably the HARDEST thing I've ever done ever since I started using computers...
Put the TT copper heatsink on, after cleaning the core with AS5 and nail polish remover, put it in...and......it worked...
It actually worked.....I was SURE I had mucked up something with all that prying and stuff....
Set core to 320 mhz and did some Quake3 for a half hour....no locks at all. (previous high was 310 mhz). Of course I don't know if it's stable at 320 mhz, because openGL stuff has always run at higher clocks than D3D(8+9) stuff. But man.....
If my Radeon9800 Pro is also glued on with superman glue, I might just give up PC gaming forever....I'm NOT going through THIS again......
Thanks to all who helped.
(and yes, I still would like that replacement fan, check your PM).