Wade, welcome.
Find your water heater on the side of the trailer.
In the front basement look at the rear wall. Could be a couple of sections, each screwed on. The section closest to the water heater - remove the four screws and near the back of the water heater you will find 3 valves to bypass it.
I use this hose and my oil-less compressor to blow out all the lines.
http://www.campingworld.com/shopping/item/blow-out-hose/38534
After that I run antifreeze through the system.
There is a hose that is fairly well hidden near the docking station that you can place in an antifreeze jug or bucket. There is also a "winterizng valve" in the docking station that switches the pump intake from tank to that hose.
I use a 5 gallon bucket and fill it up with the RV antifreeze.
Have the optional washer dryer combo?
That requires running a small load cycle to run antifreeze through the washing machine. Just don't forget to run a load or two in the spring to clean it out.