Pretty sure I looked at that model while shopping. It was dripping from under the front, found out it was sloppy work from winterizing it. That drain likely has a 1/4 turn valve on it.
That said, I read a tip about using the water heater bypass and the TT's water pump to get the majority of the water out more quickly than a gravity drain. Something you may want to google.
A visit or call to your dealer is another way to overcome the poor manual. They made $ off selling you the TT, they should help you get started.
2013 Heartland North Trail 22 FBS Caliber Edition
2013 Ford Expedition EL with Tow Package