"Everyone has a plan until they get punched in the mouth" - Mike Tyson
Well the old ball joints are finally removed, but not without putting up a fight. No amount of heat was working. Even after putting the A-arms back on the car and pressing the socket against the nut, I couldn't break them free.
Enter my good friend, the angle grinder, again. I made two cuts in the ball joint nuts - enough that I could then drive a screwdriver through. Once I relieved the pressure, the nuts finally broke free and the ball joints slipped out.
Bonus picture confirming the effort is worthwhile:
Up next: Another video demonstrating the installation of new rubber bushings and possibly torquing the replacement ball joints to spec.
Thanks!