I just did this on my Nexus S and decided to share. The ICS for nexus has begun rolling out from Google. It’s annoying that this has to be done manually for now. I did a lot of googling to find an real way of going around it. So if you have a Nexus S and want the new Ice Cream Sandwich OS on it here’s a way.
The update is for the GSM version of the Nexus S, not the CDMA one. Please note that if you are rooted or even running a rooted stock ROM, this update may not work for you. It is advised that you to revert to a completely stock Gingerbread ROM on the device and then proceed with flashing the update.
- To begin, download the update form the link above, rename it to update.zip and copy it to the root of your SD card.
- Power the phone off and reboot into bootloader mode. (Hold Volume up and the Power button.)
- Select Recovery from the menu to boot into recovery.
- When you see the warning triangle and arrow, hold the power button and tap volume up. You’ll see a menu.
- Select apply update from /sdcard and select the update.zip.
- Once the update is flashed, simply reboot your device and cross your fingers.
Your Nexus S should boot into the new ICS firmware if all goes well.