If you realize that you may have accidentally added the wrong client to a Customer Group that is being used on an appointment, you can edit the appointment to update the list of clients on it.
To remove a client from a group appointment, you'll need to do the following:
Go to the Appointments tab in your account and locate the appointment by using any of the following filters: Agenda, Day, Week, or Month.
Click on the appointment you need to update and then click on the three black dots to Edit the appointment. (This is only necessary when viewing the appointment in the Week view. In Agenda, Day, and Month view, just find the appointment you want to edit and click on the three black dots next to it.)
In the appointment, click on the three black dots next to the client you want to remove.
Click the Delete button.
In the pop-up window that appears, click OK to confirm the change.
After you have removed the client(s) from the appointment, click on the green X in the upper right corner to finalize the update.