What stated above is just about it. Basically, leave the water heater in by-pass and run fresh water through your lines until all the RV antifreeze is flushed out. Simple done.
Sanitizing is still a hot topic on these forums. Some folks are adamant about doing it, some don't care. I'm in the "don't care" group. If you are flushing your water lines with city treated water, then your sanitizing everything automatically. If you are on a home well and its not treated water, you may want to go ahead and sanitize. Or go to a campground that has city treated water and flush the system there.
Although sanitizing your water system does no harm, it will require flushing even more fresh water to get the chlorine smell and taste out. It really is just a matter of how you feel about it. In 20 years of RV ownership, I've sanitized my water systems, (3 trailers and 1 pop-up) very few times. One was the day I brought it home from the dealer. Mostly, after that, never again. But if I lived in a different environment, or a different part of the country, or had the camper parked in a storage facility where I had no control what happens to it 24x7, I probably would sanitize more often, because who knows if someone could have dropped a dead mouse into the fresh water tank fill port or not? But since it's parked on my own property, in the country, with only 1 neighbor close by, the odds of something like that happening are very, very slim.
Your choice, nothing right or wrong with sanitizing. Just remember, the stronger the chlorine concentration, the shorter time it needs to sit in your system to kill anything growing. The weaker it is, the longer it needs to sit before flushing. The stronger it is, the more you have to flush to rinse it out. The weaker it is, you won't have to run as much water to flush it out, as it's already diluted pretty thing.
I personally don't like to drink bleach. That's why I don't do it my tanks at all, unless I know I'm having a problem.... which has been never.
