When you delete a directory, all the files within that directory will be deleted as well.
Click Files (Uploads) to delete a directory
To delete directories, click Files (Uploads) in the administration menu.
Check the directories you wish to delete
In the checkbox, check the box next to each directory you wish to delete. Click the Delete button at the bottom of the list of files.
Confirm you wish to delete the directory and the files inside the directory
A confirmation page will appear reminding you that the directory will be permanently deleted. At this point, you may uncheck any directory that you do not wish to delete. Click the Delete button to permanently delete the checked directories. A confirmation page will appear with a link back to the files list.