If your data source is connected you can easily change the table data on your entire report to view the different sources (sites) you may have access to analytic data from.
If your data source is not connected you may need to add data to a Report. If you need to change a data source on a specific table you can edit a data source.
Instructions
Ensure that your report is in Edit mode
Select File, then Report settings:
Select a new data source in the Report Settings window:
Now your entire report is set to display data from the newly selected data source.