As long as you haven't paid or registered yet, you can use the Clear & Start Over account feature to remove anything you've already prepared. Here's how:
Sign in, Continue your/take me to my return.
Go to My Account (top right), Clear & Start Over.
You're asked: 'are you sure you want to clear your return?'Yes or no.
You have clicked a link to a site outside of the TurboTax Community. By clicking "Continue", you will leave the Community and be taken to that site instead.