You are pushing your luck when you change a boat's name, but in this case I think it's worth the risk. If I remember correctly, you have to go through a lot of champagne and sacrifice a virgin, but I can't remember which comes first.
There are several good resources on the web. This one looked OK to me:
Boat Name Changing Rules | eHow.com
Best of luck and don't cut any corners. "And bless all who sail in her!"