I have a contractor come in to do some tile work and he had taken out some GFCI outlets. I think he must have used a power drill to loosen the screws and one of the green, ground screw fell off. It would not go back in. Now I have 2 GFCI outlets with no ground. 

It seems the screw is supposed to screw in a small plate inside the outlet, like a screw into a nut. As the screw is completely off, it is not connected to anything. Is there a way to fix that?