Change Date of Birth

For some reasons, my date of birth was changed when I apply for a passport and U.S Visa in China. It made me one year older than my acutally age. I have been in the U.S. for 10 years. I'm holding a H1B visa, and waiting for my LC. I still want to change back to my acutaly date of birth. How to do that and when can I do it? Thanks!