You don't need to take any panels off, using the low point drains for the hot and cold lines and the fresh water tank and the drain on the water heater is sufficient. But you will want to fill the lines with RV antifreeze, using the bypass valves on the water heater after you have drained it. There are some good how to videos on YouTube from some of the larger RV dealers. Here is one:
https://youtu.be/fZshRDDVc9o
You will also want to remove your battery and put it on a battery tender for the winter.