Developers have earlier successfully ported Android Open Kang Project (AOKP) ROM based on Android 4.1 (Jelly Bean) into the Samsung Galaxy S2. Now the AOKP Build-2 version is available. Recognised developer, bajee11 from XDA Developers has released the AOKP Build-2 based on Jelly Bean for Galaxy S2 with model number I9100G. The AOKP ROM is an unofficial version and carries a build date of 17 September.
Galaxy S2 users looking to install the AOKP Build-2 ROM for Galaxy S2, can follow the tutorial below. Since the ROM is in its development stage, bugs are likely. IBTimes UK cautions its readers it will not be liable in case damage occurs to the device while installing the firmware. Users are advised to backup all important data as well as APN settings before proceeding. Ensure that USB drivers for Galaxy S2 are installed and that the USB debugging mode is enabled. Also do not forget to install the ClockWorkMod (CWM) Recovery for Galaxy S2. The AOKP ROM is only compatible with Galaxy S2 I9100G not with any other variants; therefore verify the model number of your device before following the guide.
Steps to install Android 4.1.1 with AOKP Build-2 for Galaxy S2 I9100G
1) Download Jelly Bean AOKP Build-2 ROM for Galaxy S2
2) Download Google Apps package
3) Connect your Galaxy S2 to the computer using the USB cable. Now copy the downloaded files to the SD card of your phone
4) Unplug the Galaxy S2 from the computer and turn the phone off
5) Put the Galaxy S2 into ClockworkMod Recovery while pressing Volume Up, Power and Home buttons together until the Samsung logo appears. Press the Power button to get into the CWM recovery
6) In order to backup the current ROM, select Backup and Restore then Backup again. Return to the main recovery menu
7) Now select Wipe data/Factory Reset then select Yes to perform data wipe
8) Select Install zip from SD card then select Choose zip from SD card. Now navigate to the downloaded AOKP ROM file, select it and confirm installation
9) Once the ROM is installed repeat the same process (like step-8) and this time select the Google apps package and confirm installation
10) Upon the completion of installation process, return to the main Recovery menu and select Reboot system now to boot up into the AOKP Build-2 Jelly Bean ROM
NOTE: If you wish to restore the previous ROM, then boot your phone into recovery. Select Backup and Restore to restore the desired ROM by selecting it.
Your Galaxy S2 I9100G is now running on Android 4.1.1 with AOKP build-2 ROM. You can verify the software on your phone by browsing to Settings>> About Phone.
[Source: XDA Develpers]