If you've already filed your return and need to add a W-2, you can always amend. I'll leave the steps below on how to amend and how to add another W-2.
To File an Amended Return:
1. Wait for your return to be accepted or rejected by the IRS
2. Log into your account, and at your tax timeline select your "2016
Tax Year"
3. Select to "Amend (Change) 2016 return" and
follow the directions
https://ttlc.intuit.com/replies/3288565
If you need to remove a W-2:
1.
Go to "Federal Taxes" at the top of the
screen
2.
Select the "Wages & Income" sub-tab
3.
Select "Start/Revisit" next to "Wages and Salaries"
4.
Select "Delete" next to the W-2 you would like to remove
