Download the 2.3.4 update for the G2 https://rapidshare.com/files/3796067356/PC10IMG.zip
Once downloaded, place it on the root of your SD card (not in any folders).
DO NOT rename it. Its name should be “PC10IMG” with .zip being the extension. (if its not then rename it PC10IMG.ZIP)
Turn off your phone and boot into bootloader (press and hold the power button and volume down at the same time).
Once the bootloader is up you should see the “PC10IMG” being scanned.
Wait for the phone to finish scanning the file. If done correctly the phone will ask if you want to update.
Press volume up to confirm. The update process should begin after that.
Give it a few minutes and make sure you don’t have a low battery. Shutting the phone down or pulling out the battery during an update process can potentially brick it.
Once the update has been successfully installed, the phone will ask to press the power button to reboot.
The phone will reboot and you have a freshly baked 2.3.4 Gingerbread update!
if that doesnt work then stilll download the file and put it on the root of your sd card.
then flash into bootloader
let it boot into clockwork mod.
then go to backup and restore
make a back up of your rom (incase things go south you can restore)
then go back to the main menu in CWM
choose install zip from sd (not update)
then choose the PC10IMG.zip
let it do its thing
and then you should be done and running the OTA GB