You will need to have the Full Write Events permission to perform this action.
Click on "Events" from the left navigation menu.
If you are viewing the event listing table, you can filter for the event you want to edit and click on the "View" button. If you are viewing the event calendar, click on the event itself in the calendar. For repeating events, it does not matter which occurrence you use.
If you cannot find the event for some reason, make sure you have visible the calendar the event is on. You can toggle event calendar visibility from the top right area above the calendar.
Regardless of which method you chose above, you will be sent to the event screen. Choose "Edit event" from the "Actions" menu in the top right area. A pop up will appear where you can edit the details of the event.
See this article for more information on the fields an event has.
When viewing a repeating event, clicking on the date next to the title opens a calendar you can use to quickly jump to any other occurrence within the repeating schedule. Only days in bold are valid.
How to delete a reoccurring event
Go to the event, select the Actions button > delete
You will have three options: Delete One, Delete Series, Delete Future.
If your intentions are only to delete that specific occurrence of the event, choose the first option "Delete One".