To Delete a Form
Open your return in TurboTax.
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
Do you just want to delete the W2 or start your return completely over?
How to clear an Online return and start over if you have not paid yet.https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-clear-and-start-over-in-turbotax-online/00/26444