[Sabardeyn]

LaGringa,
Just in case, my previous post was directed more toward theducks. A separate response to you was made unnecessary by a much briefer and clearer response from Kovid while I was typing. So I'll leave that alone.

I would just advise going slowly, make regular back-ups, and expect that whatever you do today might not work on another viewer/reader or different device (whatever you're using in the future). So always keep the original file safe because you may need to do this again.