When you open Web Payments you can use the Settings to change some things

Up in the top right of the screen is a drop down menu marked Settings. It has a few different options.

Change Password

You must know your current password in order to change it to a new one.

Add Bank Account

This brings up the same screen as clicking the Add Bank button available next to Choose Bank Account on the screen.

Manage Bank Accounts

This option lets you change the default bank account that shows each time you log in to Web Payments. You can also remove a bank account on your list. This means it will no longer be available to you in the list. It does affect previous payments made using that account. You can always reenter a bank account's information to add it back to the list.