It's possible that you have added a secondary event to your form after you started receiving submissions. Or maybe you simply want to change someone's response to your secondary event. Here's how you can do that:
Step 1: Go to Reporting > Overview
In your event's left navigation menu, locate Dashboard and then select Overview. At the bottom of the screen, you'll see the list of existing registrations.
Step 2: Find the guest whose response you want to edit
Locate the attendee whose submission you want to edit and click on that attendee. The box containing the information your guest entered when registering will appear on your screen. Click on 'Edit' button to make further changes.
Step 3: Change the response to the secondary event
In the dropdown menu below the ticket selection, change the attendee's response to the secondary event and save the changes you made.