1. On the left pane under Shared libraries, select the library you want to delete.
  2. Click Go to site on the upper right. You'll be taken to the Microsoft SharePoint site that houses the library.
  3. Click Settings (the gear) in the upper right and then click Site information.
  4. Then, at the bottom of the pane, click Delete site.
  5. You’ll see a notification box that explains what’s being deleted. To confirm, select the check box, and then click Delete.