In 2012, I wrote about a tool that allows you to update the data source in all the reports in a folder. It is called CR Data Source and is put out by R-Tag. The original version would only work on reports that use a single connection, which is the majority of the reports that I do. But R-Tag has just updated this tool so that it can deal with reports that have multiple connections. It will still only work with OLEDB and ODBC connections. If you want to learn more about the tool, you can check out a short video on the CR Data Source web page.