Steve,
The water should be around 6" deep 8" is a bout as deep as you should go. The top collection cup does come of. It has a threaded union joint all you do is loosen it and it comes off. You can just slide it straight off. The pump also comes off very easy. It is attached to the skimer body with a rigid plastic tube that press oon the pump and than press into the skimmer body. Total disassembly time 1 minute!