I would take the ring to a jeweler. Since it's so expensive, you really don't want to mess with it.
I've been reading that jewelers use cray / super glue to set stones before they finish the setting by bezeling, etc.
Surely, they should know how to remove it.
I have the same kind of problem on a much less expensive piece of jewerly. A small stone fell out and I decided unsuccessfully to crazy glue one in. What a sloppy mess! Now the glue is everywhere on the bracelet. I can chip some of the glue off. Now I'm going to try some nail polish remover. Ugh!