Hi,
I read a very interesting article about mega voices quite a while back on PJD's (member) website. It mentions the note event range that mega voices have. Once you know that you can get rid of those "mega" events leaving you with a non-mega voice part which means you can exchange the mega voice (say a mega solid guitar voice) for a normal solid guitar or for that matter any other normal guitar.
I open up the style with mega voice part in mixmaster and click on the voice view button. In that overview I can see wich mega voices are used and which midi channel they use. I then go to the note event view and single out the channel with the mega voice I want to work on.
Once I am in that overview I sort on notes by clicking the note tab. I then scroll down until I see note events that have the number 6 or higher behind the note name, select all of them by clicking on the first and hold shift-key while clicking on the last note with a value of 6 or higher. Then I right click the selection and choose delete the selected events.
When that is done I replace the voice either in mixmaster first before I save the style or take it to my keyboard an replace the voice there. Rince and repeat for other mega voiice parts.
link to the article on pjd's website:
http://sandsoftwaresound.net/tag/mega-voice/regards,
Peter