Since many unofficial Android 4.0.3 Ice Cream Sandwich ROMs are already hitting the android forums for old devices. Today, official Android 4.0.1 (build: XXKP4) and Android 4.0.3 (build: XXKP8) Ice Cream Sandwich ROMs with TouchWiz interface have been leaked for Galaxy S II handsets. This amazing news has come out from SamMobile a popular blog for covering mobile products by Samsung.
Please follow the below mentioned step by step guide if you want to flash any of them on your device but it is pertinent to mention here that these builds are an early versions of ICS which is not stable and only works on the international version of the Galaxy S II.
THIS WILL VOID YOUR WARRANTY!!!!. PROCEDURE WE HAVE REFERRED IS ALL AT YOUR OWN RISK. KOOLMOBILE.NET WILL NOT BE RESPONSIBLE IF IT GETS FAILED OR CAUSED ANY DATA LOSS!!!!!
1- Download ODIN 1.83 from here
It is suggested that you should extracted after downloading the firmware
1- Make sure you that Samsung KIES is completed shut down.
2- Open ODIN
3- Boot Galaxy S II into Download Mode by switching your device off then press and hold Volume Up + Home + Power.
4- Connect your Galaxy S II with PC through USB cable after which ODIN will detect it.
5- Press on PDA and choose: I9100_CODE_I9100XXKP4_CL42141_REV02_user_low_ship. tar.md5 downloaded and extracted earlier on desktop in Step 1 [Android 4.0.1]
5- Press on PDA and choose: I9100_CODE_I9100XXKP8_CL42141_REV02_user_low_ship. tar.md5 downloaded and extracted earlier on desktop in Step 1 [Android 4.0.3]
6- Click on PHONE and select: MODEM_I9100XXKP4_REV_02_CL1092599.tar.md5 [Android 4.0.1]
6- Click on PHONE and select: MODEM_I9100XXKP8_REV_02_CL1092599.tar.md5 [Android 4.0.3]
7- Now click CSC and select: GT-I9100-MULTI-CSC-OXAKP4.tar.md5 [Android 4.0.1]
7- Now click CSC and select: GT-I9100-MULTI-CSC-OXAKP8.tar.md5 [Android 4.0.3]
8- Press the START button
9- ODIN will now start flashing your selected leaked ROM to Samsung Galaxy S II. As soon as your device is rebooted, disconnect it from your PC.