I know there a few tutorials already about, however it seems quite a lot of people are either asking questions about the ADB method, or cannot understand other methods. So i’ll try and put it all in one easy to follow tutorial
For this method we are going to use Paul O’Briens Superboot.

Superboot is a boot.img that when booted, will root your device the first time you boot (installing su and the superuser APK). No need to flash any partitions, no need to mess around with ADB, no messing with the contents of your data partition, no overwriting the shipped ROM on your device, just boot the boot image using the instructions below and you’re done!

APPLY THIS AT YOUR OWN RISK! I AM NOT RESPONSIBLE FOR ANY ISSUES

Download the latest version of Superboot: DOWNLOAD

You might need the drivers, however its worth getting them anyway as you’ll probably need them in the future: DOWNLOAD DRIVERS

Windows

1) Extract the contents of the above file into C:\root

2) Power your device off

3) Connect your phone to your computer

4) Put device into the bootloader by holding down Vol Up + Vol Down + Power

5) Open up cmd and navigate to by typing to following (Hit enter after each line):
cd C:/
cd root

6) Unlock your bootloader by typing - this will wipe your device!:
.\fastboot-windows oem unlock

7) You should get a warning on your phone. Use the volume keys to select an option, and press the power button to confirm it

Your bootloader should now say that it is unlocked at the bottom

9) To root your device, double click:
install-superboot-windows.bat

10) You should now be able to reboot your phone and it will have root

Linux

1) Extract the contents of the above file into a folder

2) Power your device off

3) Connect your phone to your computer

4) Put device into the bootloader by holding down Vol Up + Vol Down + Power

5) Open up terminal and navigate to the folder used in step 1

6) Unlock your bootloader by typing - this will wipe your device!:
./fastboot-linux oem unlock

7) You should get a warning on your phone. Use the volume keys to select an option, and press the power button to confirm it

Your bootloader should now say that it is unlocked at the bottom

9) To root your device, type the following (Hit enter after each line):
chmod +x install-superboot-linux.sh
./install-superboot-linux.sh

10) You should now be able to reboot your phone and it will have root

 

OS X

1) Extract the contents of the above file into a folder

2) Power your device off

3) Connect your phone to your computer

4) Put device into the bootloader by holding down Vol Up + Vol Down + Power

5) Open up terminal and navigate to the folder used in step 1

6) Unlock your bootloader by typing - this will wipe your device!:
./fastboot-mac oem unlock

7) You should get a warning on your phone. Use the volume keys to select an option, and press the power button to confirm it

Your bootloader should now say that it is unlocked at the bottom

9) To root your device, type the following (Hit enter after each line):
chmod +x install-superboot-mac.sh
./install-superboot-mac.sh

10) You should now be able to reboot your phone and it will have root