How to access hot water heater plumbing in Fleetwood DP?

I had to replace the water tank twice on my 2007 Discovery through neglecting to drain it before cold weather split them in 2. I removed everything through the side panel on the outside. It not a complicated job. Just once it happened you would be wise enough to let it happen the second time! I now have replaced the drain plug with a drain valve similar to one on a radiator.;)