Got a W-2C from my employer, and need to amend my filed tax for 2016. Don't know where to enter the W-2C form or the corrected information

You replace the original W-2 information with the W-2C information. Do not make the change until you start the amended return. Do not file an amended return until you receive the refund from or make payment of taxes due on the original return. To enter the W-2C, type W-2 in the search box and click on jump to W-2.