The best way to delete the W-2 you do not need is to:

Login to your account

Click continue your return

On the top right corner of the computer screen you will see my account, click my account

Click tools

Click topic search, enter in 'W-2', hit your enter button

You will see the Income Summary page, your W-2's will be listed out, next to each one you will see a trash can icon, click the trash can icon next to the W-2 you do not need.