Hi, I have a problem with my bathroom. The bathroom was an addition to a 150 year old farm house, so I have no idea how long ago it was build. The toilet flange rusted out and the toilet now leaks (no we are not still using it). Because of the vinyl flooring and wall paper the water damage got a big foot hold before I noticed it. (It was my Grandmother's bathroom while she was alive and the rest of us stayed out.) Here's the question: If the sill is rotted how do I replace it? The wall is load bearing. Thank you for any instructions.