I helped a friend install a new overlap vinyl liner in their 24ft above ground last summer. Well they drained it this spring to clean it & now that they have filled it back up it, there are a few spots that are sagging down. My question is: Is it possible to pull those sides up without draining the pool? It is an overlap liner , so you have to remove the top rails to pull it over. I am afraid if i remove the top rails the weight of the water will just pull the entire liner down or rip it. Any suggestions ?