How do I make amendments to my high speed rail ticket/add-on items?

High Speed Rail Ticket:

To amend the ticket time, head to the collection counter at the rail station 30 minutes before your scheduled departure time. The staff at the station can help you amend your ticket. To amend the departing/arriving stations, please cancel your existing booking and rebook with the correct information. The travel date cannot be changed; only other trains or seats on the same day of travel can be modified. Each PNR is limited to one change only.

Add-on items:

If your ticket offers free cancellation, you can cancel and rebook your high speed rail ticket and your add-on item with the correct information. Check your voucher and Bookings page for more information on your ticket's cancellation policy. Make sure to double-check the validity of vouchers for add-on items since some add-on items are open-dated and may not require amendment.