Schuko socket (further difficulty)

You'll probably just have to drill it out unless it is a very loose fit in which case it may 'tease out' with a pair of tweezers or similar implement.

How do you drill without dethreading the hole? I can see this going badly.

Scott expressed precisely :

Try to drill or tease out the copper wire, that should leave the screw loose enough to remove. A small drill bit will follow the softer copper, in preference to the harder brass of the terminal.

use a small enough drill to fit between the threads and the recalcitrant screw can usually be got out. If it snapped when you tried to unscrew it, it would seem thatb it was overtighted by the original installer. The don't sell insulated torque screwdrivers for no reason.

Regrettably it was on the way in, so my fault. I thought it was protruding more than the others so I tried to tighten it a bit more. That said, it is solidly in now so perhaps I would just leave it be.

Very small anticlockwise drill bit is probably your best bet...

Thanks. There may be an argument for leaving well alone given it is solid but it offends my sense of neatness.

Has MK quality declined? This assembly seems very flimsy. The last plug I fitted was fiddly with a heavy cable. Even the last socket seemed a bit flimsy.

This particular device is a niche item and came from Malaysia. Is the Malaysian quality as good or am I getting more of a 'budget' product?

NT

Angle grinder :)

Dental burr in dremmel or die grinder can be controlled to drill screw or at least make centre for drill then make easy out by grinding a square taper to a point on hard steel. Anything is possible with DIY

You drill with an smaller drill to remove the central plug of the screw then ideally use an extractor tool which is reverse threaded so as you screw into it, it tightens and undoes the screw (or bolt).

Thats the theory any way ...

Someone had to say it!