If you have a 2018 RV it should have came with a owners manual, and this manual should explain the winterization and de-winterization process. If for some reason you did not get this manual a quick e-mail to
[email protected] or a call to (800) 537-1885, and you should be able to get a pdf of the manual e-mailed to you.
An important part of the de-winterization process also includes sanitizing of your fresh water system.
The You Tube Video @creativepart sent you is good information as well. I do however question opening the WH Bypass while the antifreeze is still in the system as any antifreeze in the fresh water system will be pumped into the WH tank when you open a HW faucet. I always push all the pink stuff out of the system before opening the WH bypass valve. Just my way of doing things.