To add a small detail to what's already been said.
About the only way to defeat cured epoxy is with high heat, and that obviously can cause collateral damage. I've used a soldering iron with a knife tip and won the war, but lost a battle to keep everything undamaged. As mentioned, cutting with something like an xacto saw can win the war too. Most times, how much has to be destroyed depends on how much epoxy is inside the joints you're trying to undo. When I waged my war, after it was done I decided if I ever considered doing it again, I'd saw it out and replace with scratch built replacements.

It's still unclear if the elevator is not aligned with the other elevator or not aligned with the horizontal stab in front of it (horizontal stab has the elevator attached) or if one side of the horizontal stab/elev is angled up. Just having one side of the stab with a bit of dihedral shouldn't cause anything that looked like loss of radio signal.