Hi. I have a fluval spec v and have tried to take the filter out to clean the area well. The "ball joint" that is on the fish side of the wall I feel should come off so that I can slide the tube back into the filter area and then lift the whole unit out. However, I am not able to get that piece off (it's the piece that the water flows into the tank - not sure of correct term). I have pulled and pried but I don't want to break anything. Can someone please confirm the correct way to disassemble this filter setup so I can completely remove it for cleaning.