Actually I have the 2012 29.2. On it, the low point water drain is right beside the water pump in the first compartment by the door. It is a pull up release that drains all of the lines except the hot water heater. Be sure to open a faucet to let air in and water to flow easier.
I would also do the hot water heater first. The by-pass for it should be under your bed. By-pass it by turn three valves the opposite directions. Open the plastic drain plug on the front of the heater tank outside and let it flow out. You may have to open the air bleed to speed up the water draining.
I would then put the pink stuff into your lines. I got a small plastic hose and connectors for the tie-in by the water pump at a hardware store for a couple of bucks. I stick the plastic hose in the gallon of pink stuff container and have the wife turn on the pump then go from faucet to faucet running it until it comes out pink. It takes me 2 gallons almost perfectly. Don't forget the toilet, inside and outside shower.
The whole process takes less than an hour once you know what to do.
PS - we usually take a winter trip and just use hook-ups. Flushing the pink stuff out and resetting the hot water heater and not putting any water into the tank. We use gallon water jugs to flush when not hooked up. Still have to run the hot water heater at night and the furnace to keep things above freezing, but no problems for temperatures to about 0.
Colorado '15 Winnebago Forza 34T w/MKZ hybrid toad