Earlier today, Samsung announced that Galaxy S II owners in South Korea, Poland and some other regions of the world will get to taste the official Ice Cream Sandwich update on their handset.
Since then, the official firmware (XXLPQ) has been pulled from Samsung’s server by the folks over at Samsung-Updates.com for Galaxy S II owners in other regions of the world to flash and enjoy.
Below is a step-by-step guide on how to install the official LPQ Ice Cream Sandwich firmware on the Galaxy S II -:
Since this is an official firmware, users will not lose their warranty if they flash this firmware on their phone. Their phone will however be wiped clean of all data, so please make a backup of your data before proceeding futher!
Step 2: Switch off your Galaxy S2 and re-insert its battery. Now boot your Galaxy S2 in Download mode by pressing the Volume Down + Home + Power button simultaneously. Your phone will then show you a warning. Simply skip the warning by pressing the Volume Up button.
Step 3: Start ODIN, and then connect your Galaxy S II to your PC. ODIN will then detect your phone, and display a random COM:ID number inside a glowing rectangle box. Click on the ‘PDA’ button, and select the ‘I9100XXLPQ_I9100OXALPQ_I9100XXLPQ_HOME.tar.md5’ file. It is the only file inside the zip file that you downloaded in Step 1 above.
Step 4: Do not touch any other option. Simply press the Start button and wait for ODIN to flash the firmware.
The firmware is pretty big (600MB extracted), and so ODIN will take some time to flash it. The first boot after the flash will also take considerable time. It took nearly 10minutes for my Galaxy S II to start after I flashed the firmware.
Update: Added some mirrors for the firmware download link. For root access, download and flash Siyah Kernel LPQ and flash via ODIN.
Update 2: If your phone is stuck at the S boot logo for more than 15 mins, re-insert the battery and re-do the steps mentioned above.