Download at WugFreshVERSION 1.6.4 - This program will automatically bring together all the files you need to unlock and root your device in a few clicks, or flash it back to stock and re-lock it. You can also use this program to backup/restore all your important data, flash zips, set file permissions, push and pull files, install apps, generate logcats/bugreports, and much more! With the included file association options, you can perform tasks like flashing zips, installing apps, restoring android backup files, and flashing/booting img files with just a double click! The program includes a full featured interface for automating tasks in TWRP, enhanced restore features, an in-built auto-updater/notification system, ‘any build’ mode, logcat/bugreport generation, advanced restore features, and quick tools utilities. All the latest Android builds and Nexus devices are now officially supported with full 4.2.2 support. The program intelligently and selectively downloads the files it needs for your device and makes sure you are using the latest files available. The main changes in this release are enhancements to “Flash Stock + Unroot” script, fixes to the updater, the ability to choose root with Koush’s new Superuser app, a streamlined system for updating to the latest custom recovery, and lots of general code improvements. Check out the updated changelog for a more comprehensive breakdown of the feature set in this release.
Read NZtechfreak's excellent guide for using the root kit.