When you double-click a recurring appointment to edit it, you are asked if you want to open only the current occurrence of the appointment.
If you click OK, the Appointment dialog box appears so you can edit the current occurrence of the appointment.
You can change the all of the appointments in the recurrence range from here if you decide by clicking the Change series button.
When you double-click a recurring appointment to edit it and click Cancel, the Appointment dialog box opens and allows you to edit the entire series of recurring appointments.
To change the setting of the recurrence for the whole range, click the Recurrence button.