Water tank and water pump

Water tank drain valve (yellow handle) and the water pump diverter valve (at water intake)
(Google and buy a "Valterra Water Pump Winterizing Kit")
Insert clear tube to the bottom of the antifreeze jug and turn on the water pump.
Open each faucet in turn until water turns pink.
Run the toilet water and shower head till they turn pink.
Pour a little into the shower floor drain.
Your done.