You can access and change the information provided by your customers through their booking reference number in the Bookings tab. Once you have completed the necessary search fields to find your booking you can click on the booking reference (formed of 5 random letters and numbers e.g. 2W9PY).
The next screen shows relevant information about the booking, including details for all attendees of the booking. Simply click on Edit details next to the attendee’s name to change their information.
If you're looking to fix an attendee's email address then please see here.