- Download the OTA Package
- Rename it to update.zip
- Copy it to the root of the internal storage
- Power off the device, hold Volume Up and Power to reboot into the bootloader
- Select "recovery," then hit the power button
- Once the warning triangle appears, hold the power button and hit volume up
- Select "apply update from /sdcard" and choose the update.zip
- Once the process is finished, simply choose "reboot system now"
Once it reboots, BAM! You've got ICS. Congratulations!
Good news GSM NS owners - your piece of the Ice Cream Sandwich is on its way! According to the official Nexus Twitter account, the update started rolling out today and will continue for the rest of the month.
Google's Nexus S support page has already been updated to comfort users transitioning from Gingerbread to ICS, offering helpful tips such as how to change the wallpaper, add a widget, and view recently launched apps.
There's no estimate as to when the CDMA version may be receiving its update, but I imagine that it shouldn't be too far out.
Let us know when this update hits your device!