Hello all: I am fairly new to maintaining an inground pool. We had someone close our pool at the end of the last season and in the middle of re-opening, the pool guy has become indisposed. I am trying to get it open myself and it appears all but one plug has been removed. The remaining plug is in the skimmer and is a rubberized expansion plug ( I don't know why he didn't use the gizmos I had but I am certainly not an expert). From what I can tell, he left or placed a chlorine tablet in the skimmer and perhaps the plastic wing nut on the plug has disintegrated. It feels very flimsy and I can't get a grip on it. Any tips for removing this plug? I don't want to damage anything trying to yank it out.