Winterizing

Your 08 is probably the same as our 06 29B. 2nd compartment behind the drivers door is the compartment. There is a shelf at the back of the compartment, actually over the Ford frame rail, a little hard to see with out getting on your hands and knees. At the front is the fresh water tank drain valve, large yellow handle, 90 degree open or closed. Then there is the water pump and then the winterizing line. It could be curled up and partially hidden, it's attached to the water line between the fresh water tank (which is the very back wall of that space) connected with a two way valve, pump either draws from the tank or your winterizing jug. Further back you will see another two way valve which is the low point drain for the lines on the drivers side.
On the passenger side, first compartment behind the rear wheels there are two vertical lines on the back wall of the compartment, which is directly below your shower. They have shut off valves in them, they are your hot and cold low point drains. they are open ended and terminal just below the compartment floor.

Ken