how to delete object Data Source for local (rdlc) report?

I've created a couple of data sources and now would like to remove one on a local (*.rdlc) report, how do I go about doing this? Just to clarify, these data sources are for a local report in a smart client application (report made in VS2005 Report Designer, and not SQL Server 2005 Report Designer), they are found in the report's Data Sources window (not the applications) and can be accessed/assigned by the local report (Report > Data Sources...) - where you can remove the data source from being on the report, but not completely remove from the project.

Any help is appreciated.
Thanks.
PeterSorry, it was a newbie question. Found why I couldn't delete the extra data source, it was an XSD data source that I created outside of the Data Source folder, and simply lost track of it.