Bypassing the hot water tank depends on whether your hot water tank has a bypass valve (or valves). This should be adjacent to the hot water tank inside the RV. If you don't have a bypass valve, there are simple to install bypass kits that will add a bypass valve to your hot water tank. Also easy to install is a winterizing kit which is a valve and tube that is installed at the intake side of your water pump. You connect the tube to the valve, turn the valve and put the other end of the tube into the RV antifreeze bottle. Turn on the pump and the pink stuff runs through through your plumbing. With this you will use a few bottles of antifreeze and the process is quick and easy then to winterize.