It is very easy to add/remove a bank from the Banks dropdown in the main menu of AccountsPrep!
In the image below, you can see that both banks have a 'gold star' icon to the left of their name. This means they are included in the main menu dropdown for quick access. Click the star to turn it grey, and this will remove the bank from that menu.
See the quick demo below where we have two starred to begin, and then remove one from the menu, before adding it again.