Start by emptying then flushing your holding tanks. If you are starting this while you are connected to a sewer hookup, you are all set. Otherwise you will need to find a dump station.Next you will to drain your fresh water tank. The drain is located usually quite close to the fresh water fill location (not to be confused with the city water or hose connection). You may have to look under the trailer, in a storage cabinet or under a seat or bed in the RV. While the fresh water tank is draining, take the plug out of your hot water heater. The most common type is a plastic plug. The easiest way to remove the plug is with a 7/8" socket and extension. Other types of plugs may require different tools. Leave the plug out for now. On the back of your water heater is the water heater bypass. Before bypassing your water heater, note the position of the valves. There may be between one and three valves depending on the type of bypass. The type or quantity doesn't matter, change all the valves to the opposite position.If your water heater doesn't have a bypass, you will need to install a temporary bypass kit. This kit consists of a short hose and a couple of connectors. You will need to disconnect the two lines connected to the hot water heater and connect them to each other with the kit. If this is an RV that you are planning to keep for a few years you may want to consider installing a permanent water heater bypass kit.Next look underneath your trailer for two protruding pipe stubs sticking straight down a couple inches apart. If you have them these are low point drains. If they are capped, remove the caps. If they are uncapped, then there is a valve you will need to open directly above them in a cabinet or under a seat. When finished close or recap the low point drains. A note of caution here, if the caps are black iron or copper instead of plastic you may have found the LP gas system instead of the low point drains.If your RV does not have low point drains (many do not), it is recommended that you blow out your system with an air compressor. You will need a blow-out plug for this, you can get one from and RV dealer for $4 or so. If the air compressor is regularly used for any kind of air tools, make sure that the automatic oiler is bypassed or turned off. Set the complessor for 40 psi or use your water pressure regulator before the blow-out plug. Now have someone hold the air nozzle on the blow out plug while you go around to each faucet and open it until water stops coming out. Don't forget your toilet, shower, outside shower ice maker, etc.Now you will need to pump non-toxic antifreeze through you water lines using your 12 water pump. Perhaps the simplest way to accomplish this is to dump 6 ot 8 gallons of anti-freeze into your fresh water system. You can save most of that by bypasssing the water tank. Take a look at your water pump. If you are unsure wheer it is, turn it on, open a faucet and listen. If you are lucky, your RV already has a pump winterizing kit installed (rare). If not you will need to disconnect the hose from the suction side of the pump and in most cases simply connect a three foot long piece if 1/2" hose (you may need to purchase $2 fitting). Stick the suction hose directly into a jug of anti-freeze and turn the water pump on. One by one open the cold then the hot on each faucet until you have a steady flow of pink. Don't forget to lift the shower knob in the tub. Now Do the toilet, outside shower and any other water fixtures you have. Finally open the bypass valves until a little if the pink stuff runs out of the hot water heater. Turn the pump off when finished.Put a cup of antifreeze in your sink and shower drains to winterize them. Wipe up any antifreeze left in plastic or fiberglass bowls or showers as it can stain if left there over the winter. Don't forget to put the plug back in the water heater and put a cap on your outside water connections to keep out bugs. That's it you are done!brass ball valve brass fitting