1.) Navigate to the Take Attendance tab and click on the blue 'Choose Existing Event' button. 

2.) You will see a list of existing events. Click on the event you want to edit. 

3.) You will be brought to the event page. Click the link for 'Advanced Options.'

4.) Type in the new event name in the provided box and click the green 'Update Event' button. 

5.) You will be brought back to the event page. The title should now show the updated event name.