Root Google Nexus 4 on Android 4.2 Jelly Bean

Requirements
These instructions are viable for Nexus 7, Galaxy Nexus, Nexus 4 and Google Nexus 10, running Android 4.2.1 JOP40D. Make sure you have

• One of the supported devices with an unlocked bootloader
• SuperSU binaries
• ClockworkMod Recovery 6.0.1.9
• Android Debugging enabled on your device
• ADB installed with fastboot
• At least 70% charge remaining on your device.

 Recovery image.
Procedure
Step 1: Connect your device to PC and put the SuperSU ZIP package at the root of the internal memory.
Step 2: Place the recovery IMG file at a convenient location on your computer.
Step 3: Reboot your device into bootloader mode, and make sure it is still connected to the PC.
Step 4: Launch a command prompt session, and navigate to where you placed the recovery image. Run the following command:

fastboot flash recovery recovery-clockwork-6.0.1.9-grouper.img

where the last part is the name of the recovery file. If you choose to rename the downloaded file for ease, change the name in the command accordingly.
Step 5: Now, select recovery from fastboot menu, and you’ll be taken to the newly-flashed ClockworkMod recovery. Choose Install ZIP from SD Card, followed by Choose ZIP from SD Card.
Step 6: Point to the SuperSU package and flash it.
Step 7: Once flashing is complete, reboot the device.