Christine, without being able to see what's behind the walls and under the floors, there's probably a good chance that this can easily be done. If you are considering this as a DIY project, you should start by reviewing a good book on the subject of plumbing. Even if you are having it done, you might consider this so you will have a feel for what the job will require and the names of the parts required. Plumbers are big on continuing to use archaic names and local variations so just having a dictionary of terms they use will help.