I would like to make a modified pool pump cover for my Hayward super pump to attach my shop vac to blow out the lines. What is the best way to accomplish this? Should I just use a hole saw (ones for doors) and then stick an adapter in there that the vacuum can hook up to? Considering the lid is curved should I just put a bunch of silicone where the fitting will attach to the cover in order to create an airtight seal? Anyone who has one and could post a pic would be greatly appreciated. I don't want to screw up a $60 lid.