At this time, you cannot delete a bank account as a payment method. You can mark it as non-active and will not show as an available payment option.
To disable a Bank Account:
- Click on the Payment Methods tab
- Click on the bank payment method you would like to disable
- Un-check the Active? checkbox (and un-check Default? if it was also the default) and save your changes.
You can then proceed with adding a new bank account if necessary.