Changing payment method

Currently I have 3 numbers on my account which is paid monthly via my credit card, I need to cancel 2 of the numbers due to a change in circumstances.
How do I change the address and payment method for the remaining number.

MikeM you can change your payment method via your My Lebara app by going to the payment methods section. Any issues let us know here.

Martin, sorry I forgot to add this properly, I also need to change the lead name on the account and the billing address, is this also possible via the app.
Basically the account is myself, my wife and my brother in law, my wife and I are moving to France full time and want to cancel our contracts and the put the account in my brother in laws name at his address not ours.