Last few week, Samsung has released the Android 4 OS upgrade to Samsung Galaxy S2 in many parts of the world including Asia and Europe, the users in United States are still awaiting its release in the market.
Today, there’s some good new for AT&T Samsung Galaxy S2 SkyRocket owners as the Android 4.0 ICS update has already leaked for the device.
According to RootzWiki, the Android 4.0.3 ICS build is dated March 14 2012; so, if you decide that you have waited long enough to upgrade to ICS, hit the download link below and manually install it via Odin. Here is the instructions to upgrade Samsung Galaxy S II Skyrocket SGH-I727 to Ice Cream :
Note: This is unofficial updates, use them at your own risk as they are known to not be 100 percent stable. This firmware ONLY compatible with the AT&T Samsung Galaxy S2 Skyrocket, model number i727. Before start, please backup all contact, sms, apps, etc.
Turn Off Galaxy S2. Then turn Galaxy S2 into Download Mode by press the Volume Down + Volume Up + Power button until warning icon appear on the screen. Then press the Volume Up button to enter Downloading Mode.
Open i727ucalc4-oneclick.exe file to run Odin on your PC, which will be used to flash the firmware on your phone. Then connect your Galaxy S2 to your PC via USB. Yellow bar in the Odin COM:ID column indicate that Odin detect your phone. (If Odin not detect your Phones, then you can refer here (Link) for how to solve)
Click Start button then upgrading Galaxy S II Skyrocket SGH-I727 to leaked Ice Cream Sandwich ICS 4.0.3 I727UCALC4 process will be started.
Wait until finish and odin show PASS!
you have Ice Cream Sandwich ICS 4.0.3 on your Samsung Galaxy S II Skyrocket SGH-I727 now
Source: Root RootzWiki