Thanks Mac

Your suggestion on the second idea would be good. So just to make sure I understood completely:

For example, I have a 2 bar riff on bar 7 and 8, and the original style is called "FAB"

1. Open style FAB and save/rename it to FAB_new.
2. Working on FAB_New, use Style editor to edit the first 2 bars so it becomes the exact performance of the riff on all parts. (this is the bit I am not sure. shall I edit the first 2 bar and remove the rest, or keep the first six bars and edit only bar 7 and 8.
3.When happy with FAB_New save the new style.
4. Open style FAB (the original) then import chords, melodies etc.
5. On bar 7 choose "Style Change" to style FAB_New.

I guess this also works on customised ending and opening.

Thanks again

LJ