Any changes to the relationships MUST be done logged in as the User.
If you are installing an Add2Outlook update, reinstall the new version over the older version.
If upgrading Add2Outlook, you do not have to delete the relationships first, as Add2Outlook will save them and reuse them, as long as the relationships are going to the same source and destination and the accounts are active. Your relationships will remain there intact after the upgrade and the upgrade does not change the rules of the relationships. If you are upgrading MS Outlook, uninstall the older version of Add2Outlook, upgrade Outlook and then download and install the correct version of Add2Outlook that matches your version of Outlook.
If you delete a relationship, make sure the user account you are deleting is still active (not disabled), and the Exchange Server (or other calendars) are available and online or the destination copies will not be removed.
Go into the Console and Right-click the Relationship and click Delete.
Tip: If you are completely removing Add2Outlook, be sure to delete all the relationships from within the Add2Outlook Console first so it can remove the tied copies.
Confirm this is the relationship you desire to delete. If you press OK, Add2Outlook will ask you to confirm the deletion, and give a reason for the deletion.
Press the Delete Button to delete (pressing enter will not delete the relationship).
During the deletion process, during the next sync, all the copies of the source item will be removed from the destination calendar.