If it is breaking up that you want to do, just leave him with his mother and be done with it. He is not in your house. This should make things easier. Don't let the "steps" get in the way. I know that it is not quite as easy as I speak, but we often way over analyze things and make mountains out of molehills by over-analysis. Really, if it is breaking up you want to do, then, he's already gone, so it is 90% done.