Hello! I'm looking forward to getting my pond going in the next few weeks if the weather cooperates. It was a brutal winter here with temps far below zero for a period of time. I didn't expect my 2 goldfish to survive but I have seen one of them swimming around a little. Everything I've read says I should disassemble my pump and clean it before starting it up again. According to the owners manual, there are 4 screws located on the rear that are supposed to be loosened in order to disassemble it. The problem is, there are no heads on those screws. I can remove 4 screws on the inlet end but they don't seem to have any effect. What am I missing here? Do I have it all mixed up? If I can't disassemble the pump to clean it, will it be OK to just reconnect it and start it up? Thanks in advance for any help!