Thanks for the quick reply!
I need to post a proper introduction of myself and our rig.
We have a 2006 3684FL. Best 5th wheel or trailer so far for me. It has the living room up front with two slides there. I'm pretty tall so having the spacious bedroom and shower in the back is perfect. You don't see many of 5th wheels with that setup so I was glad to find this one.
Except for the damn black water problem. Small price to pay.
I guess you mean I should just go ahead and cut the plastic pipe, install the new valves (or seals) and then glue in a small section of pipe. Is that right? That might be the safest as I'm afraid all our push, pulling a prying might damage the surface between the valve and the tank (or pipe.). Its so darned close to being free we keep thinking we can just jiggle our way to freedom. However taking the time to actually cut the drain pipe may make the reinstall safer and more secure.