Hi,
OK, I was attempting to fix a leaking cold water shower head. I turned off the water at the road, removed handle & flange. Removed brass thing that was screwed into shower pipe.

Took to hardware store, they replaced rubber washer and gave me a tool to remove the seat from the pipe . Well it is stripped and I could not get it out. So I just put everything back together hoping for the best. Within 2 days, the handle itself and the head were leaking very badly :( .

Obviously the seat (metal ring screwed in pipe inside wall) needs to be replaced since you could see a worn place in it. How am I ever going to get it out? Is there any way?

This is a very old ceramic tile shower and plumbing is most likely 30 yrs old. I cannot find a cutoff valve to that bathroom or shower. There is not an access without cutting a hole in the wall on the other side. I even looked under the house for a cutoff.

I can't afford a plumber for at least a couple more weeks and water is pouring out now.
Thanks for any suggestions.

(I can send pictures if it will help)

"Obviously the seat (metal ring screwed in pipe inside wall) needs to be replaced since you could see a worn place in it. How am I ever going to get it out? Is there any way?"
The faucet seat,(see image) has a square hole that a seat wrench,(see image) fits into. If the square hole's rounded off or stripped I then take a screwdriver the will silip into, but not through, the faucet seat and tap it with a hammer so it binds in the hole. Then I cac take a large pair of pump pliers and turn it out. Since both seal and valve body are made of brass there's no danger of the seat being rusted in. good luck, Tom