As long as you haven't filed yet (or you e-filed, but got rejected), you can change your refund method.
- Open your return in TurboTax.
- Go to the File section in the left menu.
- Next to Step 2: Your refund info select Revisit.
- Choose your desired refund method and select Continue.
Unfortunately, once your e-filed return has been accepted or you already mailed it, it's too late to change your refund.
There's one exception: if you chose to apply this year's refund to next year's taxes, you can request a check refund instead.