I recently moved into a home with a pool that seemed to maintained ok. I cleaned the cartridge filter and it looked like it hasn't been cleaned before. I am trying clean what I believe to be what is called a pool pump. It's part of the filtration system (it's supposed to catch large items such as leaves). It seems to be filled up with leaves and I think its clogging up the whole system because water is pumping out really weak. The problem is that I can't open the lid on it.Any tips ?