change data source for an .rdl file

Hi,

I created some reports that have different data sources.  I realized I should have created shared data sources instead, so I converted a data source to be shared.

How do I modify my rdl files to point to the new data source?  I thought I would be able to do this in BIDS, but I don't see where.  Do I need to recreate the report? 

thanks

edit - I found that I can change it on the report server, but how to I change the data source in BIDS so they match?

thanks