KORG PA4X 76 - Manual (Page 451)

Writing the Sounds |447
▪ To save over a Factory Sound location, deselect the Factory Protect check-
box in the Global > Mode Preferences > Media page.
When replacing a Factory Sound, please be warned that all Keyboard Sets,
Styles and Songs making use of it will be modified as well. Use this feature
with great care!
▪ To restore the original data, please use the Factory Restore command in the
Media > Utility page.