Whats the best way to get a backplate screw out that has its screw head broken off?

if it’s not too tight in there it can be removed with some heat and a dental pick. Heat up the area around the screw on the case and not the screw.

I got lucky on this one. Unbelievably, as the screw head snapped off, it left a perfect slot in the screw! A small laptop screw size screwdriver fit in there perfectly and came out with zero resistance.

I had to buy a new block to get one out once. Bought a motor off ebay and it had a tap broken off in one of the backplate holes. Guy said he'd seen it run, uuuh nope you didn't.