Screws won't tighten on the skimmer plate. Sheet metal wall behind skimmer rusted out. Need to stop the leak. Do I drill new holes between the existing screws, or remove the screws and replace with bolts? I will make four piece backing plate to sandwich the liner. I've lowered the water lever below the skimmer. I will pull the deck up again and dig the sand out from around the skimmer to access it.