If you have not filed your return yet, go back to the Personal Info, click Edit on your Name, check the box that you are claimed on someone else's return.

If you have already filed your return & it has been accepted, then you would need to amend your return to make the change.

How to amend (change or correct) a return you already filed

https://ttlc.intuit.com/community/amending/help/how-to-amend-change-or-correct-a-return-you-already-...