3.4. Editing, Moving or Deleting an Existing Event
To Edit or Copy an event, select the Edit button that appears next to the event in question at the top of the screen for that day. Similarly, to Delete an event, select the appropriate Delete button. For repeating events, you can choose whether to edit or delete all instances of the event, or only the instance that occurs on the day you're looking at.
If you're Editing an event, you'll be presented with the same Event Edit Form used to create a new event. The fields will contain information for the event to be edited, and you can change any or all of them. When you're ready to save your changes, press the "Replace Event" button.