Accessing NTFS HDD through samba

I'm having trouble writing to the HDD attached to my pi from my laptop. The samba share is set up fine it seems, since I can write to the SD card without a problem. But whenever I try to write to the HDD from windows I get a permissions error. This is the ls -l /media/ output:

drwxr-xr-x 1 root  root    30 Jan  1  1970 .
drwxr-xr-x 1 root  root   158 Feb 20 20:00 ..
drwxrwxrwx 1 xbian xbian 4096 Feb 18 19:56 ExternalHDD
lrwxrwxrwx 1 root  root    18 Jan  1  1970 usb0 -> /media/ExternalHDD

I've tried to umount the drive in order to remount it with different permissions, but it says the drive is in use. I've run fuser -vm on the directory and this is the response:

                     USER       PID  ACCESS COMMAND
/media/ExternalHDD:  root     kernel mount /media/ExternalHDD
                     root       4919 ..c.. smbd

I'm guessing the 'smbd' refers to samba, but I can't work out what command I should use to stop it, so I can't stop it being used. I'm sure the answer is around on this forum somewhere already but I'm not experienced enough to apply other answers to my own setup. I've also tried to modify the /etc/samba/smb.conf file, since that was the problem on a previous setup, but it now says "DO NOT EDIT THIS FILE" so I figure it's probably best not to edit the file.

How can I stop the samba share, and how would I mount the HDD with the correct permissions?

Also, could someone explain what the 'usb0' entry is? It just appeared and I'm not sure what it's for.

Thanks for the help.

My linux distribution is xBian, which I believe is based on Debian. I used the script on this page: http://ift.tt/17GoDJH to install a public samba share, because whenever I personally followed the steps it didn't work. It's reasonably basic, it just installs samba and adds a section to the /etc/samba/smb.conf. It has worked on previous installs.