Hey! Sorry I am just now seeing your question. Hope you have found it by now! if not, my recollection is there is a quarter turn spigot at about floor level on the driver side wall at the back of the coach just below the fill nozzle for the tank. Ours actually broke and we replaced it right before we traded it!
Ours was a 2001 Infinity. We didn't winterize as it was always plugged in with a space heater on in the winter. Great motorhome!!! Would still have if we hadn't wanted to downsize!!!Let us know if we can help with anything else!