You can delete the old one and enter the new one.
Here are the steps for deleting unwanted forms in TurboTax Online:
Open your return in TurboTax. (To do this, sign in to TurboTax, and select the Take me to my return button.)
In the left side bar, select Tax Tools> Tools.
In the pop-up window Tool Center, choose Delete a form.
Select Delete next to the form/schedule/worksheet and follow the onscreen instructions.