To start with I’d probably get two blocks of wood and hold the thing in the vice, get a tiny punch and see if I can tap it out? If it isn’t seized it should be quite easy to unwind
If it's a steel screw, the Ti is where you got lucky. Dissolve it out with ferric chloride.
If the screw is Ti too, you're going to have to take your chances with mechanical extraction, left handed drill bit seems to be the most consistently successful
Does anyone know of a way to remove a sheared 4mm threadlocked screw from a titanium spindle?
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