Conversion of Canadian QBooks to U.S. Version

I have a client who originally set up and used QuickBooks on their own, but started with the Canadian version. They did this to help with currency conversions, since they do business world-wide.However, we have now taken over all their bookkeeping and accounting work, and we want to convert them to the U.S. version, hopefully as of January 1st, 2008. I would love to be able to actually convert the file, so we keep the historic data, but is anyone aware of how to do this? Is there any utility you may know of that does this automatically? Any help would be greatly appreciated!