Hi Bob
The way is the same for all the <possible to copy files>:styles, multi-pads, registration, midi..
Load on YEM your pack / Make the PPI/CPI and install on keyboard / change what you want and save (same or different name) on the keyboard user area not in folder Expansion / copy these files on the USB STICK / go to the computer and (Erase original files if you want to replace) / <import Content> to your pack.
Export like PPF if you want to keep like this. Make a new PPI (don't forget to add manually the added file install and check.
Success!
Mihai