Hi - i just bought a 2008 Maxum 2700SE with a 350MAG SeaCore engine (glycol cooled). During the mechanical inspection it was noted that the Water Distribution Housing was cracked where the blue plug threads in. Long story short - the boat was delivered to me with the new part in a box. I'd like to install it myself and I'm just wondering if I need to drain anything before unclamping hoses, etc. If so, what should I be opening to drain this; just the blue plug or? Is there anything else to be opened to allow venting for faster draining? Will I be draining glycol or is this on the sea water side? Please respond if you need any clarification from me. Thanks!