Im trying to use an FTP Client to remove the "Forums" folder off of my site but I keep getting a pop-up and it says

550 Can't remove directory: Permission denied : /forums/store
550 Can't remove directory: Permission denied : /forums/images/avatars/upload
550 Can't remove directory: Permission denied : /forums/images/avatars
550 Can't remove directory: Permission denied : /forums/images
550 Can't remove directory: Directory not empty : /forums

Can anyone help me.. Please..