You cannot change it in TurboTax. To just update your direct deposit information, see the following from the IRS.
The IRS does not have my direct deposit information. What can I do?
In the coming weeks, Treasury plans to develop a web-based portal for individuals to provide their banking information to the IRS online, so that individuals can receive payments immediately as opposed to checks in the mail.
https://www.irs.gov/coronavirus-tax-relief-and-economic-impact-payments
