Google has started pushing Android 2.3.4 update over the air to Nexus S Phones. But if you don’t want to wait for the update notification, you can manually apply the official update via recovery now.
Guide to update from build GRI40 to GRJ22:
- Download the update from Google servers
- Rename the file to update.zip
- Copy it to SD card.
- Switch off your Nexus S
- Reboot in bootloader using Vol UP + Power Button
- Select recovery by using Vol buttons and power button
- A triangle with exclamation mark will come, now press power button and Vol Up at the same time to bring recovery menu.
- Select “Apply Update from SD card”.
- Your work is done, go chat with your friends in video now.