I have a new toilet I want to install but water supply line comes out of the wall behind the tank. The pipe coming out of the wall is probably 1 inch and there is a bushing to get it to 1/2 inch copper. It's an old house with plaster walls and galvanised steel pipes. I'm thinking I need to cut into the wall and make the transition from 1 inch to 1/2 inch inside the wall. Then I would have to re-tile part of the wall.
I took a picture but not sure if it uploaded so here is a link.