If you've already filed and your return has been accepted (or mailed), it's too late to change your bank account for direct deposit.
If you have not yet filed your return, you can easily edit the account info you wish to transfer your money into before you file. Follow the instructions in the link below.
https://ttlc.intuit.com/community/accessing/help/how-do-i-change-my-transferred-direct-deposit-information/00/27040