You can change your direct deposit information either by calling the CRA at 1-800-959-8281, through your financial institution, or through the CRA’s My Account, which you can login to here: https://www.canada.ca/en/revenue-agency/services/e-services/e-services-individuals/account-individuals.html
If you are mailing in your return, you can also change your direct deposit information by filing in the Direct Deposit Enrolment form and mailing it in with your return. You can find the form here: https://www.tpsgc-pwgsc.gc.ca/recgen/form/inscription-enrolment-eng.html