Install Android ICS 4.0.3 on Nexus S [Official]
ICS 4.0.3 brings performance improvements and bug fixes for couple of stuff. It also includes new APIs for video stabilization, etc.
Watch ICS 4.0.3 on Nexus S in action:
How to Install Ice Cream Sandwich 4.0.3 on Nexus S
1. Download official zip: http://android.clients.google.com/pa…o/VQ8PQk_V.zip [128mb]
2. Rename it to update.zip.
3. Mount USB storage and Copy it over to the internal storage on your Nexus S.
4. Power off, then hold volume up and power to reboot to the bootloader.
5. Use the volume key to navigate, select recovery, then use the power button to select.
6. When you see the warning triangle and arrow, hold the power button and tap volume up. You’ll see a menu.
7. From the menu, select “apply update from /sdcard”, and choose update.zip from the list.
Wait till it updates your system, radio, and other partitions. When finished, choose “reboot system now”
Bingo, you now have ICS 4.0.3 running on your Nexus S.