Nothing could be easier! 
First, go to our ticket office. Then, when you validate your basket, you have to tick YES to the option "Payment in instalments". Then enter your bank details so that the payments can be made. You will be debited each month from your first payment.

To exchange your ticket, go to your order via the link "Manage my order" that you received in the confirmation e-mail sent to you.
If you can't find this email, you can have it sent again here. 
Then click on "Additional actions" and then on "Change tickets".
Then the system will ask you which ticket(s) you want to exchange. When you confirm the ticket you want to exchange, on the next page you will see the passes and day tickets you want to exchange.
If you exchange a day ticket for another day ticket, for example, you do not have to pay any extra. Please note that only certain exchange options are possible depending on the type and availability of tickets.

You will need to wait until all payments have been finalised before you can exchange your ticket. 
Once the payments have been finalised, the procedure is the same as described here: I want to exchange my ticket
 

No stress! Here's a link where you can have this email sent back to you. 
This is just an order confirmation. Your tickets will arrive in your mailbox on 15 July at the earliest. 

Ticket upgrades are only possible with tickets bought online on our official ticketing service. 

Here is a link that will allow you to change the name on your ticket.