I was naturalized in 2011, and then I left the US to attend college abroad. I was informed last year that I am supposed to change my citizenship status with the social security office. I was supposed to do that this year when I go back to visit the US, but unfortunately I was not able to go. Is there any way to do this while I am outside the country? Or is it possible for me to appoint a representative (power of attorney) to do it for me instead?