Screw from the connection + cable defective, how can I get it out?

Hello, I got me an old Signat Mark 2 Mark II, this works as far as perfect, only one problem I have. And indeed I gave the screw the grace shot when connecting the plus cable So the Signat does not have a connection for a cable with a cable shoe, but those, in which one goes directly with the cable and then fixed with a screw (made screw or as the name is) . However, this screw was already very round and when I screwed firmly, the cable was seems not to be far enough in the terminal and so I turned the screw empty, and that is until it is standing down. But now I can’t get it out anymore, as the screw is already too round as I said. What possibilities do I have now to get it out? Can I maybe weld a screwdriver or the like on the screw and then turn it out? Yes, I know, on such an idea only I probably come up with, but otherwise I don’t really think of anything. Gi bt also these pastes that you put on the screw so that the screwdriver doesn’t spin any more, but it didn’t do anything. Otherwise, I just remembered to drill the screw out (from the front) and then solder the cable (so fill the terminal with solder and then put the cable in). But if that’s how it works? What would you do? MfG, Diddy