Oh my gosh - I forgot that I need to do this as well! I think that we just email customer service our new information but I am not positive. Hopefully Chris or Cathe will get a chance to answer this.
I had to do the same thing because I moved in December. I e-mailed [email protected] with my old and new address. Someone (Nancy) replied the same day. She needed the invoice # or the approximate date of the pre-order to process the address change.