I have a couple of Advance tickets between London and Rye and hold little hope of successfully completing the journey next week. According to the Southern website : " If you have opted to collect an Advance purchase ticket via TOD, but have not yet collected it, you may change it to a different date online without change fee (though any fare difference will still be payable and the new ticket must be between the same two stations" Can someone advise how you perform this change? When I select a ticket it merely tells me its not refundable and sends me to a link with older more restrictive rules. Do I just collect the ticket and take any train I want? I'm using the app or mobile site.