Replacing black water cable valve

I changed one on a previous trailer and I want to say it was a bear. On this trailer I had to cut an opening under the valve location. Getting the exact location was not easy. Removing the old valve was relatively painless but getting the pipes spread apart to install the new valve to get the seals to set right was extremely difficult. I had to redo the install three times before it didn't leak (i just filled the tank with water to test). I actually used the old bolts and nuts to spread the pipes far enough to slip it in place. I sewed the opening shut with wire ties. Hopefully, your install won't be as involved.