I am an international student, and I accidentally claimed AOTC. Can I know how to amend my tax return, I have to file 1040NR instead of 1040. I already got the refund

I did not know I have to use other tax return to file taxes. Instead I use TT and filed as 1040. I just read that I have to file with 1040NR and have to refund AOTC. I already got the refund from IRS.