Download and Install the Android SDK in your computer, download the Superuser and Clock Work mod Package and copy them into “C:/Android/platform-tools” folder.
Connect your Nexus 7 to the computer and enable USB debugging by navigating to Menu>>Settings>>Developer>>USB debugging. Open the command prompt in your computer by pressing the “Win + R”, enter “cmd” and press enter to start the command prompt. Enter the below mentioned command
adb push path-to-zip/JB-SuperSU.zip /sdcard
cd platform-tools
Reboot your device by entering the following command:
adb reboot bootloader
fastboot oem unlock
Select “unlock” to unlock the Google Nexus 7
fastboot flash recovery path-to-img/CWM-grouper-recovery.img
After your device has booted up, enter the following commands to make ClockworkMod Recovery permanent on your device:
mv recovery-from-boot.p recovery-from-boot.bak
via: xda-developers