First follow the steps in articles 5.1, 5.2 and 5.3/

Change repeat/group appointment

It is not possible to change a single appointment in terms of date because the pattern cannot be interrupted. You can change the time.

Delete repeat/group appointment
It is not possible to delete a single appointment because the pattern cannot be interrupted. In this case, the entire series will have to be deleted and re-entered.

Instead, change the status to Canceled.