Pretty sure mine was epoxied in. If you look closely at the threads on my pic above, you can see they were badly stripped. Getting it out even when I had access to most of the shank was not easy. Acetone soaking is the best "safe" way to dissolve glue, including epoxy. I tried that but when the fluid can't physically reach the points of contact between the threads it can't work.
There is a drill bit tool called an "Easy Out" with which you can drill into a stuck screw. It has reverse threads that unscrews the stuck screw while it sinks into it. But finding one small enough and strong enough to drill into a mangled steel screw head is not likely. I did look for one. Even if a jeweler has one, I doubt it would overcome the epoxy bond on the other end.
Cutting the links off is quick work with a dremel and metal cutting disc. Maybe practice first on a piece of scrap metal like a thick washer, etc. Hold the links in vice grips, wear gloves, aim and cut. About 15 minutes later the bracelet is back together minus the extension links.
I had to cut out a jubilee link for the same reason, that took some real care because each link is 5 separate parts. The single SD43 cut is very straightforward.