Step 1:

1. Download and install the USB drivers from the Samsung website: Support - Sprint Cell Phones SPH-L700 | Samsung Cell Phones
2. Download the root files "Superuser zip" and "TWRP img": Sprint Galaxy Nexus Root files

NOTE: For this rooting method to work your handset needs to have an unlocked bootloader. This process is not covered in the following guide.

Step 2:

1. Connect your Galaxy Nexus to your PC via the USB cable.
2. Copy the "torosp-root-tool.bigrushdog" zip and paste it onto your handset.
3. Unplug your handset from the USB cable.

Step 2:

1. Power off your Galaxy Nexus.
2. Press and hold both volume keys and the power button at the same time.
3. Once you've accessed the bootloader connect your Nexus to your PC via the USB cable.

Step 3:

1. On your PC, navigate to the folder where you've downloaded the root files.
2. Hold the "Shift" key > right click on an empty space on the screen and click on "Open command window here".
3. In the CMD window type "fastboot devices" without the quotes and hit Enter in order to verify whether or not your PC recognizes your phone. If a line of numbers and letters appears then you're on the right track.
4. In the CMD window type "fastboot flash recovery TWRP212.img" without the quotes and hit Enter. The "TWRP212.img" file is one of the two root files you've downloaded earlier.

Step 4:

1. Once the flashing process is over in the CMD window you can unplug your phone.
2. On your Galaxy Nexus press the "volume down" button to switch to "Recovery mode" and press the "power" button to select the option.
3. After your phone reboots tap the "Backup" button on your phone's screen.
4. Make sure that "System", "Data" and "Boot" options are checked, and then swipe the round button at the bottom of the screen. This feature will create a backup of your unrooted system so be patient as it takes some time.
5. Once the backup has been successfully completed tap the "back" button on the screen then tap the "back" sensitive key on your device.
6. Press the "Install" button and tap the "torosp-root-tool.bigrushdog" file in the list.
7. Swipe the round button at the bottom of the screen to begin the installation process.
8. After the installation is completed press the "Reboot System" button.

NOTE: The first reboot after flashing might take a while.

9. If you've successfully rooted your handset the "Superuser" app should be available in the "apps" menu.