You can change your payment details anytime through MyAccount. You just need your email address provided to MyRepublic as your username and the password you created during the signup.
If you can't remember this information, don't worry- we have a way to retrieve them. Just click here
To change your payment details, click 'MyDetails', and then 'Payment Method' and then 'Change Payment Method'.
Just fill out the details of the new credit/debit card and click on Save Changes. This will apply the changes to your account.