Delete a Data Source
You cannot delete a Datasource which is associated to an app.
- This is to ensure that you do not break an existing app -
Disassociate the Datasource
To delete the datasource you need to disassociate it from the app.
Go in the feed section of the App tress and select 'New / Remove Data Source'
This will bring the window which lets you remove the association of the data source to the app.
Select the Data Source then select Remove.
Delete the App
You can also Delete the app.
However, when you delete an app they aren't truly deleted and for that reason you will not be able to delete the data source until the app is actually fully deleted (still associated)
They go in the 'Deleted App' basket (this allows you to recover a delete app... that comes handy more often than not)
To delete the app, check this tutorial: Recover or Fully Delete Apps
Once the app is fully deleted you will be able to delete your data source.