If you want to edit an event, go to its ''existing events'' tab.
Click on the "Administration" tab
Select "edit" under the "plays" section.
From the events list on your right, select the play you want to edit.
Click on the "existing events" tab.
The fields with the pencil icon can be edited.
Also, by selecting an event, you can click on the relevant links at the bottom of the page and make the changes you want for the selected event.