Winterizing my Coachman Concord?
We don't have one but,
Drain the water out of your coach. Empty freshwater tank, empty the water heater and set it's bypass valve(s), open the low point drain(s), and open all faucets to get as much water out. Also, drain your waste tanks.
Some use air pressure to blow water out of the lines and that seems to be enough for milder climates.
But, I live in Northern Michigan, so ...
Then close all of your faucets.
Are the valves in the wet bay area labelled? Often they can be set for winterizing. We had a Coachmen class c and it had a fitting to hook up a hose to suck up antifreeze (pink) out of a container. If not there is a fitting you can buy. Turn on your water pump and start filling the lines with antifreeze.
Then one by one, turn on each faucet until you get pink antifreeze flowing out of each one for a few seconds. Don't forget the sink sprayer and outside faucet. If you had quite a bit of clear water flow out before the antifreeze, drain your grey water tank again.
If you need you can pour some more antifreeze down the sinks to fill the p traps and put some in the gray water tank too. And, the shower. And, dump some down the toilet to get some antifreeze in the black water tank.
It is pretty straightforward. You'll get the hang of it after you do it.
For the first time you might ask someone to show you how.
2013 FleetWood Expedition 38B