1. To edit an event, you have to be first on your admin account.
2. Press on the Event tab ( ) from the left side of the page.
3. Then press on the List tab ( ) from below in order to see all events.
4. Then press on the Edit button ( ) on the right of the wanted event.
5. Here you can modify the wanted fields. After modifying the fields, press on the Update button in order for the changes to take effect.