I filed as independent, but this was wrong. How do i file differently in my 1040x

[MinhT]

If you claimed as a dependent by someone else, you must amend your tax return to indicate that fact. 

When amending, revisit the My Info section of TurboTax and edit your personal profile by clicking on Edit next to your name in the Personal Info Summary. On question 3, A few other things we need to know, check the boxes as indicated on the attached screenshot.