You can start over with the Clear & Start Over feature as long as you haven't paid or registered yet (free users are asked to register their accounts before they file).
(More info on clearing and starting over: https://ttlc.intuit.com/questions/2586254-how-do-i-clear-and-start-over)
@haggards You are correct, you can't use the Clear and Start Over option if you've already paid.
However, your data will be handled correctly in whatever version of TurboTax you use, unless TurboTax tells you while you are entering that this particular form is not handled in this version, prompting you to upgrade.
If this applies to you, click this link for info on Why Do I Have to Upgrade?
If you need help with your return, click this link for info on how to Contact TurboTax Help.