Go to Favorites > Families and edit the appropriate family.
Edit the appropriate Payment Plan for the family. PRO TIP! Remember you can double-click any record to edit it!
This will take you to the Edit Payment Plan page. Click the Toggle On/Offline button and this will remove the External Payment Profile payment type if it is already selected. If you are adding an online payment type select the External Payment Profile. Click Save and Back to confirm this and you are done!