How to uninstall NTFS-free?
Here's the official uninstall script:

#!/bin/sh

sudo rm -R /System/Library/Extensions/ntfs-free.kext
sudo rm -R /sbin/mount_ntfs-free
sudo rm -R /System/Library/Filesystems/ntfs-free.fs

if [ -f "/sbin/mount_ntfs_original" ]; then 
 sudo mv -f /sbin/mount_ntfs_original /sbin/mount_ntfs
fi


Source: http://ftp.jaist.ac.jp/pub/sourceforge/n/nt/ntfsfree/uninstall.sh