As long as you haven't filed yet (or you e-filed but got rejected), you can simply step through the File section again to choose a different method.
However, once your e-filed return has been accepted or
you already mailed it, it's too late to change your refund unless you
chose to apply it to next year's taxes (in which case, you can request a check refund instead).
If the info you provided is for a closed or invalid account, the government will mail you a refund check.
If the info you entered is someone else's account, don't worry – some
banks won't deposit tax refunds into accounts where names don't match
up. The best way for you to track your federal refund is to call the
IRS at 1-800-829-1040.