The entire process is simple and easy.
All you need to have is:
- ClockWorkMod Recovery installed (If you don't have it, you need to flash it with NexusRootToolkit)
- Newest SuperSUv1.51
- Download and put the SuperSU package to your device (/emulated/0)
- Shut-down your device
- Reboot into bootloader by pressing Powerbutton+volume down
- Using volume+/- select recovery mode and proceed by pressing the power button
- Wipe cache+dalvik cache
- Select install .zip
- Find the SuperSU zip and flash it.
- Select NO on "Disable stock recovery flash" option!
The root access is now retrieved! If you don't have the ClockWorkMod recovery yet, please download the NexusRoot Toolkit and flash the CWM recovery first.