The "pink stuff" RV antifreeze gets pumped through every line, hot and cold, in your camper. If you hook up city water, the city water will flush out all the "pink stuff". You'll have to "pump the pink" again to winterize again. Your pump (itself) may not need to be winterized again, but the rest of your lines will. You are winterizing much more than just your water pump.
Attach a hose to the in-take side of your water pump. Put the end of the hose in a gallon of "pink stuff". Turn on your water pump at the switch and turn on each faucet one at a time till "pink" comes out of each faucet ... hot and cold. Bypass your water heater, otherwise you'll be pumping 6 gallons into the water heater. By-pass, you'll put nothing in the water heater. Drain the water heater completely and just leave it.

