Note: Only Super Admins can do this.
You can only delete a document folder if it has no documents saved under it.
To delete a document folder:
Expand 'Company' in the side navigation.
Click on the 'Settings' tab in the Company Menu
Click 'information' in the Settings tab menu
Under documents, find the relevant document folder.
Delete the document folder by clicking on the bin icon.
Confirm the deletion by clicking on 'Delete folder'
All done.