Accidentally filed saying I could be claimed as a dependent. How do I amend this so I qualify for stimulus checks?

I just filed my tax return but accidentally checked yes when asked if I could be claimed as a dependent by someone else even though I can't. I'm 25 and make more than 40k/yr. How do I amend this so that I can qualify for the next round of stimulus checks if there is one? I don't see a box to change this answer on the 1040x form.