A good sonic cleaner with hot water and some penetrating oil will likely knock that out for you. Just take the saddles off the bridge, drop them in and turn it on for about 5-10 minutes. Regardless of how you get them out, a TINY drop of anti-seize on the adjustment screws will keep that from happening again. Don't get crazy with the anti-seize. That stuff is like herpes. It gets everywhere.
