[Here's a picture][1] of what I'm talking about. There is this kind of tube that prevent me to use any kind of wrench to unscrew the nut in it. But without unscrewing it, I cannot get the faucet out of its place at all.

Is there a simple trick, or tool, that would allow me to go up there unscrew it. That tube is ~ 5 to 6 inch long.


  [1]: https://imgur.com/a/4x4lDf0