Splitting Up Harmony from One Staff to Two or More Staves

Hello Everyone,

So I have this midi score, and the harmony and melody are all combined onto one staff. I would like to separate it out two different ways, so I could just have one score for piano (two hands, two staves), and then another score with piano accompaniment (two staves) plus and additional staff for the melody.

Is there an easy way to do that? It wouldnt be so bad on smaller pieces, but sometimes I run into this problem with longer pieces too, which would take forever to process.

Any recommendations on how to handle this?

Please let me know.
Thank you!

wm