The hexagonal screw on the back of the double-rock electric guitar that adjusts the height of the bridge has no prongs in the center and needs to be replaced, but where do I go to buy it? How do I rep

The hexagonal screw on the back of the double-rock electric guitar that adjusts the height of the bridge has no prongs in the center and needs to be replaced, but where do I go to buy it? How do I replace it? This is best to find a mechanic to get it, the idea of screwing out the screws before you can change the mechanic, the mechanic has a way, if you can't find a mechanic, you can try it yourself, use pliers to clamp the screws hard to see if they can be hard to screw out, if not, there are two other ways, one is to open a slot on the flat surface of the screws, and then use the screws with the screws to unscrew the screws down, the slots can be used with a saw blade, or a small flat file, to make a slot, the screws will be screwed down, the screws will be screwed down. Make a slot. Another way is to make the screw round side with a saw blade or file to make two planes (two opposite planes), and then use a wrench to try, can be stuck in these two planes, then use a wrench to screw out (may only be stuck a little bit, so, slowly card and then screw)

Screwed down, and then, according to the length and type of the original screws, and then with a suitable socket head cap screws on the line