Daniel Leeman commented,
Credit to Daniel Firlej (Finale forum contributor) who helped me out with this via email! select first staff menu item "Utilities\Change instrument..." left arrow down arrow right arrow down arrow ...
Daniel Leeman created a post,
Hello, I am using Finalev25 with Mac OS X El Capitan. I would like to do batch instrument changes with FinaleScript. I am able to select the instrument, open menu item "Utilities > Change Instrume...