You’d just upgrade from ACF4 to ACF5 Pro using these instructions… I can’t find the old instructions for going from 4 to 5Pro. Only from 4 to the beta of 5 free version. I’m not sure where they went but I posted the steps in this topic, though now I don’t know if they will still work. But they should. https://support.advancedcustomfields.com/forums/topic/field-groups-missing-after-upgrading-to-pro/
