The solution for those with a hard to reach valve handle is to just add an electric valve. Stand at the edge of the coach and flip the switch.
"DannyA"....the black plumbing is just PVC. The ends are glued on and then a valve attached. You can by those ends new, cut the old ones off, extend the entire pipe to a new location and glue the valve connector ends back on. Any good RV parts store will have a listing of various shapes and configurations of the black tank ends, openings and sizes. I did this on a trailer for a friend because her was leaking. Had to glue new valve ends on and then replace valves.