In efforts to allow two users to sync calendars to their iPhones I inadvertently bulk linked the second user as a contact not as a user. A lot has happened since then making reverting to a back up unrealistic. So, I have two issues. One, how can I bulk unlink a contact or organization from appointments? Two, how can I make the main business calendar sync to both of our iPhones retroactively and by default in the future?

Any and all assistance will be greatly appreciated.