Edit existing score wizard without creating new score

[bachstudies]

It would be fantastic if, after creating a score with the wizard, you could edit the information in the wizard to, say, add another voice part to a staff, add or remove an instrument, change the language, paper size etc. without creating a brand new score. Either that, or have the ability to easily add a new voice part or instrument via a menu option without needing to enter the Lilypond code which might be daunting for a novice.