North Dakota: I need a copy of my boyfriend's social security card. The only problem is that I his last name on his social security card is different from the one that is one his birth certificate. I went to the social security office and they told us that he would have to do a legal name change to get his last name the same on both documents. However, I have no idea how to do a legal name change. There is no form you can simply fill out, and there is no information ANYWHERE on how to start this process. The other issue we have is that he was born on the reservation. Please someone help us.