When filing my 2016 taxes, using Turbo tax, I unintentionally did it by using my 2015 w2 form. Now that it's filed what will happen since there was a different amount from 2015 to 2016,
Please reference this TurboTax FAQ for how to amend.
Then, to delete your previous entry and add your W-2 while working in amendment, please reference this TurboTax FAQ. At Step 4, click the delete button next to the W-2 you entered previously. Then, enter your 2016 W-2.