I just completed a full head replacement on my 2010 R25 SC, which included replacing all the hoses/fittings for both the sanitation and inlet raw water sides.
You can see pictures in my gallery.
The original sanitation hose (white and very rigid) was hard to remove as it was set and the turns would not flatten. I had to cut in smaller sections, put rags at each ends to prevent smells/discharge and haul out (makes sure to remove all the cable ties securing the hose in place). I used an oscillating tool with a metal cutting attachment for the hose and where the hose connected to barbed fittings.
I ran a line from where the hose goes through the deck of the washroom, under the sink and outboard of the water heater to the holding tank. I attached the line to the hose (on the outside) with electrical tape. You'll need a helper, whom fed the line from the washroom and I gently pulled in the STBD lazarette where the water heater is. Then I pulled to the holding tank and connected to a new 1 1/2 fitting to the holding tank (with two hose clamps).
The new hose I used is G380B-150 1-1/2" PREMIUM BLACK RUBBER SANITATION. It allows for 6" radius curves and is very easy to work with. The only issue, is that its outside diameter is bigger than the original white hose, which prevented to put the sanitation and raw water inlet hose in the same thru-deck hole in the washroom. As such, I made another hole for the raw water inlet hose and the sanitation hose is by itself in the original thru-deck hole.
Hope this helps, let me know if you require further details.
