I have an inground SWG pool. I have at least 4 screws that have rusted away that hold the liner track in place, which is causing a section to droop. These screws are under the overhang of the concrete deck, so I am unsure of how to replace them. Any suggestions on how to repair this? What do these screws screw into? Could I change a section of this horizontal liner track to a vertical track? I'd like to avoid cutting into the concrete if possible.