Detaching the metal hose to attach to the bidet

I recently got a FooFoo bidet and am trying to install it. So far, I have removed the seat, placed the bidet, turned off the water supply, drained the tank, and loosened as many nuts and bolts as I can find, but the metal "hose" (I guess that's what it's called?) that attaches the toilet tank to the wall doesn't detach from the toilet or from the wall at all. It appears to be cemented into both. As I said, I've loosened all the nuts and bolts attached to the "hose." How do I detach this "hose" so that I can attach it to my FooFoo bidet hose?