This software update, dubbed as GRH78, is meant to replaces the previously available firmware GRH55 on the handset. Regarding the update, the official changelog shows the following, “This system update from Google contains important bug fixes plus the latest version of Maps.”
If the automatic updates haven't shows up on your Nexus S yet, you can perform the update manually by dialing *#*#checkin#*#* from the dialer to force your Nexus S to check for the software update and download it.
Or, you can downloading the update from Google's servers here, then follow the step-by-step instruction to perform the update as below:
- Rename the downloaded file to Update.Zip
- Place the file in the root of your SD Card
- Switch Off your Nexus S and reboot into the bootloader
by holding volume up and power button - Select Recovery
Use the volume buttons to choose "recovery" from the list, and select it by pressing the power button - Choose to update
When you see the triangle on your screen, press volume up and power button once more and you’ll have a list of options, choose to update
However, if manually updating the phone isn't your style, of course, you can just simply wait til the update notification comes on your phone :)