bdvs

Hello, I know that this is a supid sounding question. I have been a pool owner for over 15 years. I have gone through 2 liners, 2 polaris's, 2 salt water systems, 6 pumps, etc. In other words, I no novice. We had to replace our salt water system *after only three years) and both pumps during summer start up. To make a long story short, our pool developed algea while waiting on repairs. Once fixed, I elected to manually vacuum the pool to waste in order not to stir up the dead alge. Now that I'm completely finished, I cannot remove the vacuum skimmer cover from the skimmer. Yes, the pump is completely off. Any suggestions. Dear Hubby has even tried to remove with a pipe wrench.