You can get a kit for about $15 which will allow you to pump antifreeze into your system from just below your water pump.   You can pressurize your whole system and run the washer and dryer, as well as your icemaker a cycle or two to get inti freeze into the system.   Usually with only a couple gallons of antifreeze.   This is how I have done it and never had a problem.   Then spin cycle as you have to get the water out of the pump resivour as well.

You may have to add a small piece of braided reinforced water hose into the loop to clear where the inlet goes into the coach.   It is far better than removing the access panel located in the back of the closet in the bedroom, removing the hoses and hand pumping antifreeze into the washer/dryer.

Some people just use air in the system to purge all the lines, but I like to be on the safe side.   If you do use the air pressure, use some form of regulator, don't pressurize the water lines with more than 40 PSI, most compressors will put out 125 psiand you could blow fitting with that kind of pressure. CAUTION! Newer D's with the 10/16 gallon hot water heater should NOT use air pressure as you can damage the blender valve.
-Submitted by Herb Petersen