Delete a PowerPivot Data Feed Library
You must be the site owner to delete a data feed library. If the library contains items, they will be deleted along with the library.
You must know the name of the data feed library you want to delete.
Delete a Data Feed Library
Click Site Actions.
Click Site Settings.
Under Site Administration, click Sites libraries and lists.
Click Customize "<your library name>"
Under Permissions and Management, click Delete this library.