Not sure if my info will help (mine is a '94LY). First, open a faucet and blow air into the street water connection. This will clear that one foot or so of pipe to the water pump. My water pump is located under one of the dinette benches. There should be a Y valve there that will allow you to attach a short piece of clear plastic tubing into a jug of potable antifreeze. Then your pump does the job of drawing the antifreeze throughout the system. The only other thing is to bypass and empty the hot water tank. There are 2 steps here: first, there is a combination of 3 plastic valves - one one the inlet, one on the exit and one on the bypass. Make sure the inlet and exit valves are closed and the bypass is open. (The bypass is a short pipe with a valve that connects between the cold water supply and the hot water outlet of the hot water tank. Then you have to drain the hot water tank. This is accomplished by removing the cap on the outside at the bottom of the tank. What I have done, and I recommend, is to replace that plastic cap with a brass one that has a small brass drain cock. This makes the annual winterising much easier. So with the drain cock open, release (open) the pressure relief valve on the top of the tank - the water should drain out. Don't worry if there is a 1/2 inch of water left in the tank - it won't be a problem.
Pump the "pink stuff" through your system, going from one faucet to another. Make sure that all the pipes are filled by making sure that you have pink stuff coming out. As well, make sure it runs through the toilet (those valves can be a costly proposition if they are cracked by water trapped in there freezing. Make sure it flows though the shower, and that you have poured some in every drain.
I've followed this routine with my '94LY and RV's that I had before without an incident. I found that the first time I did it to any rig it took considerable time, as I had to remove the caps and put in the drain cocks, as well as methodically figure out where things were. For subsequent years, the whole task takes about a 1/2 hour.
1987 Excella 32-foot
1999 Dodge Ram 2500HD Diesel