This guide is for rooting your Sprint Nexus S 4g using the stock Google (NOT Sprint) Android 4.1.1 Jelly Bean firmware. There are important differences between the stock carrier firmware and the stock Google firmware – the stock carrier firmware has protections and scripts built into it to prevent you from installing your own recovery firmware. The Google firmware does not – I would highly recommend first restoring the phone to stock Google firmware before rooting the phone.
Start with the phone powered off (hold power – select “Power off”). Turn it on by holding the “Volume Up” button and then pressing the power button. You will get to the Android bootloader screen.
Open up fastboot.exe from android tools directory. Depending on what version of Windows you’re running and the installer options you selected, the fastboot.exe binary will be in one of the following directories:
C:\Program Files (x86)\Android\android-sdk\platform-tools
C:\Documents and Settings\[username]\Local Settings\Application Data\Android\android-sdk
Open up a command window in this directory by going to C:\Program Files\Android\android-sdk\ and then shift-right-click the “platform-tools” directory, and then selecting “Open command window here” – you will now be dropped into the Windows shell prompt in the same directory as your five image files and the fastboot.exe binary. If you are running a version of Windows prior to Windows 7, you will need to open a command prompt and manually navigate to that directory.
Unlock the bootloader on the phone with “fastboot.exe oem unlock”
C:\Program Files\Android\android-sdk\platform-tools>fastboot.exe oem unlock
OKAY [ 66.851s]
finished. total time: 66.852s
On your phone, press volume up to select “Yes” then press the power button – all data will be erased from your phone! This is done as a security measure!
Go to http://www.clockworkmod.com/rommanager and download the latest ClockworkMod Recovery image for the Google Nexus S 4G. You can use either the standard recovery or the touch recovery. Download it to the platform-tools directory from above.
Flash it with “fastboot.exe flash recovery recovery-clockwork-touch-18.104.22.168-crespo4g.img”
C:\Program Files\Android\android-sdk\platform-tools>fastboot flash recovery recovery-clockwork-touch-22.214.171.124-crespo4g.img
sending ‘recovery’ (3464 KB)…
OKAY [ 0.436s]
OKAY [ 0.513s]
finished. total time: 0.950s
Relock the bootloader with “fastboot.exe oem lock”
C:\Program Files\Android\android-sdk\platform-tools>fastboot.exe oem lock
OKAY [ 0.052s]
finished. total time: 0.052s
Now boot it up into Android and enable USB Storage. We will need to download the Superuser binary and put it on the phone’s internal memory so we can install it using ClockworkMod Reovery. The Superuser website is http://androidsu.com/superuser/ – you will need to get the “ARM Devices” full build – don’t get the “binary only” build. Save it on your computer and transfer it to the Nexus S 4G’s USB storage.
Reboot into ClockworkMod Revoery by turning the phone off (hold power – select “Power off”). Then turn it on by holding the “Volume Up” button and then pressiong the power button. You will get to the Android bootloader screen. Pick “RECOVERY” with the volume up/down buttons, and select it with the power button. After a moment you will see the “ClockworkMod Recovery” program come up.
Select the option for “wipe data/factory reset” and do a wipe and reset on the phone. Don’t worry, this doesn’t erase the internal storage where the SuperSU binary is on.
Pick “install zip from sdcard” and then “choose zip from sdcard” – if you don’t see the Superuser zip file that you copied over, you may need to scroll down to see it.
Once you’re done installing the Superuser application, hit “go back” until you see “reboot system now” – reboot the phone, and you’re all set! Once you set up the phone again, you will now have root on your Nexus S 4G.
Did you find any of the information useful? Have I helped you save a bit of money / time / frustration? I've spent a lot of time taking pictures and meticulously documenting everything to post it here. I'd really appreciate it if you could send me some money via Paypal! This helps defray the cost of running this website and also provides me with beer to continue writing these articles. Thanks!