Because the adapter is the wrong mount and has slipped past the normal lock position, the safest advice is not to force it. If you twist too hard, you risk damaging the Sony mount or release mechanism.

One reported approach is to reattach the lens to the stuck adapter to give yourself better grip and then apply slow, careful turning pressure while pressing the release button. That may let it back out.

However, the safest and most sensible option is to take the camera to a local repair shop or send it in for service so they can remove the ring properly. That avoids turning a stuck adapter into a damaged camera mount.

Going forward, this lens needs the correct T-mount adapter for Sony A-mount; T-mount lenses are not one-size-fits-all at the camera end.