You can login to your order through the Customer Service tab, here you can:

• Re-send your confirmation email
• Add tickets to your order, subject to availability
• Transfer your order to another date and/or time, subject to availability, up to 48 hours before you are due on trail
• Change your delivery / email address
• Download your tickets
• Contact See Tickets

You can find the customer service page here - https://christmasatblenheim.seetickets.com/customerservice