You can easily remove a Contact By by merging it into another exiting one, and add a new Contact By to the Contact By dropdown. These instructions will first show you how to add a new one, then it will show you how to merge an old Contact By into the new one.
1. Search for a member you want to add a contact to or modify an existing contact for
In my example I'm going to modify an existing contact for a 'Contact By' who I want to get rid of (Ben), so I'm doing a SEARCH>CONTACTS and setting the 'Contact By' to 'Ben' and then picking any of the people from the results
2. Select the 'Contacts' icon for the member you want to modify
3. If your want to modify an existing contact, select the 'Edit' icon for the contact
If you are just going to add a new contact skip this step since a 'New Contact' window will already be displaying on the left
4. Below 'Contact By' to the right of 'New' enter in the new 'Contact By' that you want to add
Note: there is a 10 character limit to 'Contact By'
5. Select 'Submit'
Now that you have added the new contact we can go in and remove the old one
6. From the 'Setup' dropdown go to 'Data Cleanup' then select 'Contact By'
7. To the right of the 'Contact By' you want to remove, choose the new one you want to merge it into from the 'Merge To' dropdown
8. Select 'Merge'
Now all the contact with a 'Contact By' previously marked as 'Dawn' in my database will now be marked as 'Tony'