Apparently Android 4.1 is the latest official firmware which Nexus S users will see on their devices. However, with the freedom of Android and very active community of developers we are able to have custom ROM’s. Thereby, only a few days after its release we already have unofficial Android firmware 4.2 that comes with all stock apps that came with Nexus 4.
If you can’t wait to try new version of Android 4.2 “Jelly Bean” but you don’t want to replace your Nexus S and buy new device, this tutorial will guide you trough steps of updating your Nexus S device.
Update Nexus S to Android 4.2 Jelly Bean
Step 1: Since this is a custom firmware, you will have root access on your Nexus S before continuing with the process.
Step 2: After obtaining root access, you have to download the Android 4.2 ROM to your PC from this link.
Step 3: After downloaded the firmware from Step 2, connect your Nexus S to the PC via the original USB to MicroUSB cable and copy the firmware file in the root of your SD card.
Step 4: Now you have to start your Nexus S in recovery mode. If you have made the root with One Click, then you can go to the CMW application and restart the device into recovery mode.
Step 5: To move into the recovery options you have to use keyboard volume up and down to select it, and power buttons confirm. Knowing this, you should select “Wipe data / factory reset”, select then select “Yes”,
Step 6: In next screen go to “Wipe Cache partition” and again select “Yes”.
Step 7: Then you have to choose “install zip from sd card” and select the Android 4.2 ROM you uploaded in the root of your Nexus S SD card.
Step 8: The update process will begin and end after few minutes. Once the update process is finished you will have Android 4.2 Jelly Bean on your Nexus S.