Step #1:
Log in to your Checkbook.io account.
Step #2:
Go to "Settings" on the bottom left-hand side of the page.
Step #3:
When in Settings, click on the "Accounts" tab.
Step #4:
From the list all the Bank Accounts linked to your Checkbook account, select the ones you want to delete (select using the first column)
NOTE: The Default account cannot not be deleted until you add a new account and make the new bank account the default account.
Step #5:
Once a selection is made, click "Delete"
