1. Login to Eurostar official website: Enter Eurostar official website and find the option of "Manage your reservation" on the homepage.
2. Enter the order information: enter your order number and last name, and then click the "Findmybooking" button.
3. Select the itinerary to cancel: On your booking page, find the itinerary you want to cancel, and then click the "Change Itinerary" button next to it.
4. Confirm the cancellation: On the next page, you will see the details of the cancellation, including the refundable amount and cancellation fee. If you are sure you want to cancel the trip, please continue and follow the instructions on the page to complete the cancellation process.
5. Apply for a refund: Once you successfully cancel your trip, you can apply for a refund from Eurostar. Usually, Eurostar will process the refund within 3 working days after receiving your application.