I am trying to replace the shower head on some older plumbing. Problem is, Ive removed every piece of the shower head, but only a ball (for the ball joint of the shower head) remains on the end of the pipe coming from the wall. I cannot see threads. Is this a common thing for old plumbing. Would the only solution be to tear the wall and change the piping. Or are there threads that I cannot see for the ball. If so, what kind of tool could I use to get a could grip on it and remove it. Thanks.