Remove and reinstall black tank?

I liked what a previous poster said about the floor jack and bringing the tank down with the vent attached to it. Once down you can saw off the vent if you want the tank out from under the trailer and then dremel out what is left of the pipe in the tank. One thing to be aware of is that both your grey and balck tanks probably vent through the same line so they are joined somewhere; find that before you drop the tank so you know what you’re dealing with and if you have to disconnect that first.

Recruit help, two people will make this much easier!