Were your returns accepted? If not, you will not be able to amend your return.
Also, don't open your return. Open your tax software & on the first page on the left below the box with the returns listed, it has Amend a Filed Return. With that said the amendment form (1040X for Federal) is not available in TurboTax until late February or early March. You would have to wait until the form becomes available to amend a return.
