Modify Email Address - Marketpress

Hi - I have a customer who has placed an order but entered the wrong email address, so did not receive the confirmations.

I have modified the shipping email in his user profile, but how do i amend the email address for the one used in the order? I checked the post-type=mp_order table in mysql but it does not have the user details within this table.

Where would I find to modify the email address used by a customer an existing order?