It is possible to change your tickets! You can do so via your MyOrder page. You can find this option by following the next steps:

• Go to the button "Manage Order" in the confirmation email.
• Click on “More Actions” and select "Change tickets".
• Select the ticket you would like to change. The price of this ticket will be converted into credit which can be used to buy the new ticket
  Please keep in mind that if the new ticket is of a lower value than your credit, the difference in price cannot be refunded.

Once the change is complete, you will receive a new order number with the new ticket(s). 

Please note that only the main buyer can change tickets.