I've tried to take it off with the pump running, I've opened the air release valve on the filter, I've closed the valve from the pool... I cannot get it off. I'm not the strongest person in the world, but I've always been able to get it off before (with a struggle). The handles are nearly impossible to hold on to without crushing my hands. Any ideas to get this darn thing off? Thanks! Here's a pic of it: Hayward Power-Flo Matrix Strainer Cover SPX5500D | Hayward SPX5500D