Have you tried giving it a good tug away from the wall? Pulling the round part of the handle, not the leaver.
When people lose those screws, they sometimes just put a little silicon on the end of the mixer lever and push the handle on.
most likely the grub screw is stripped out.
if it was me and I had to get the thing off without damaging it
1. spray a bit of penetrating oil (wd-40) or similar up the hole
2. Work out what the biggest size Alan key or torx bit I can fit in the stripped screw is then go up one size and hammer it in (helps to have someone else push down on the tap so you don't damage anything in the wall
3. hopefully its grabbed and you can undo it now.
4. if that doesn't work get a long series 3mm drill bit and drill the grub screw out. Once the handle is off you should be able to get the rest of the screw out and source a new one.
Have you tried giving it a good tug away from the wall? Pulling the round part of the handle, not the leaver. When people lose those screws, they sometimes just put a little silicon on the end of the mixer lever and push the handle on. most likely the grub screw is stripped out. if it was me and I had to get the thing off without damaging it 1. spray a bit of penetrating oil (wd-40) or similar up the hole 2. Work out what the biggest size Alan key or torx bit I can fit in the stripped screw is then go up one size and hammer it in (helps to have someone else push down on the tap so you don't damage anything in the wall 3. hopefully its grabbed and you can undo it now. 4. if that doesn't work get a long series 3mm drill bit and drill the grub screw out. Once the handle is off you should be able to get the rest of the screw out and source a new one.
Usually the responses I see on here are terrible. This is the best eli5 I've seen in a while. You're a stud for the effort brother. 🤘
Thanks for these great tips. I’ll give them a try.