If it's made like the genuine, then the screw on the case back directly underneath it will be holding it in place.
If this is the case, unscrew the screw on the case back and then the screw on the front should be loose and you can reseat, then screw in the screw on the case back again to hold it in place.
If the rep also has this design feature, it is probably water-resistant too, but get that tested