Do not forget to dewinterize your RV before using the water system.
Attach fresh water fill hose to your city water fill. Turn on the water to a small stream, you can increase it later.
Slowly open all your cold water faucets and allow water to run about a minute after all the antifreeze is flushed out. Close cold faucets and repeat procedure on the hot water side. Close all faucets. Run water in toilet for about a minute after the antifreeze is flushed out. Do not forget shower heads and outside fixtures.
Turn off water and detach hose from city water fill. Attach hose to fresh water fill and fill water tank at least half full.
Open kitchen cold faucet and run water pump about a minute to clean antifreeze out of pump.
Reinstall water heater drain plug. Buy new anode rod if yours is disintegrated. Close the pressure relief valve. Turn the water heater bypass valve to the open position. Be sure to fill the water heater before turning it on.
If RV is equipped with washer/dryer, flush lines out into washer basin. Drain, run a short cycle with clean water and drain.
Sanitize the fresh water system.
Install new water line filters and water pump filter.* If you have an ice maker, check with a qualified service center on how to flush our the antifreeze in the lines and hook it back up.