How do you remove dead skin that is brown from tanning?

I just had surgery around my belly button to discover that I have a bladder disease, but anyways I went tanning for prom and now i have a dark circle of brown skin around my belly button, but its all dead skin that is tan , any suggestions that could help remove the dead skin would be much help to me. I am seventeen and I really want to wear my bathing suit without all the dead skin surrounding my belly button. Thanks! :)