Water lines in my CS 24R are blue for cold fresh and red for hot. Once I figured everything out with support from this great forum, I used 2.5 gallons of antifreeze including the amount I poured into each drain trap (sink in kitchen and bathroom, the inside shower and a little in the toilet to show that it had been winterized).
In my initial trial and error effort I did get antifreeze in to the hot water heater but I figure I can flush it next year. No antifreeze entered the fresh water tank.
I drained the black and grey water tank, rinsed the black water tank and drained it again.
I drained fresh water tank. There's a capped, short blue hose to the left (when facing the water/sewer compartment) of the fresh water fill/local water connection and beneath the remote water pump switch. I purchased an adapter at Ace Hardware that allows attaching a standard garden hose to it, removed the cap, attached a garden hose and turned on the water pump to drain. You can drain without the garden hose but the water stream strikes the inside edge of the compartment.
I drained the hot water tank by opening the pressure relief valve and removing the white plug at the bottom of the tank.
I removed the panel in the exterior storage compartment at the rear of the coach to access the rear of the hot water heater.
Sorry, picture isn't so clear. There are three valves in the lines here and one is behind a hot air duct near the top right of the rear of the heater.
I positioned the valves at the hot water heater for Winterized Position as in this diagram from a posting by from FW28z.
I extended the rear slide out and removed a single screw from the hinged compartment under the mattress marked "Not a Storage Area" and opened the compartment.
I had purchased a "T" valve that's intended to go in the line between the fresh water tank and the pump and allow one to draw antifreeze into the system through the pump. I think a piece of garden hose and same adapter I used to drain fresh water would work just as well.
There's not sufficient room between the pump and tank to install the valve as it was intended to be, however. Instead I removed the poly cap from a hose that routes to the water pump from the top of the hose, installed the T valve there and closed the valve in the line from the fresh water tank to the pump.
After firmly securing the cap on the T valve and leaving it in the open position I attached the included clear hose to the valve and placed the open end in a jug of antifreeze.
Starting with the galley sink I opened one faucet (one hot, one cold at a time) and turned on the water pump until I had antifreeze coming from the related fixture. I did learn that one must first have antifreeze flowing from the the bathroom sink faucet in order to lift the small collar and divert flow to the shower.
Don't forget the external "shower" if installed! In my case before I completed this process the outside temperature had gone from 64F to 15F in 24 hours and the hose froze solid. I had to put a propane heater on it to finish the job.
Lastly I'll be removing and storing the engine and coach batteries rather than leaving them on a trickle charger in the rig.
Hope this helps anyone with a similar system. Again, thanks for everyone that replied to my "urgent" thread and especially to for the detailed description and diagram from FW28z included in this post.
PS This is my first effort at a post with pictures. I'll try to make smaller next time.