Installing Samsung firmware can be confusing at times because it is one of the manufacturers that doesn’t offer firmware files from its website. There are tools out there to help you install firmware such as SamFirm_Reborn Tool, Bifrost – Samsung Firmware Downloader Tool, or Frija. If you don’t use a tool that will automatically locate the firmware files for you, you will neeed to flash them manually with the Odin flashing tool.
Note: ConsumingTech will not be held responsible for any damages or loss of data during the process. Install at your own risk.
Install Android 4.0.3 Ice Cream Sandwich on Unlocked Samsung Galaxy S II i9100
Step 1. Download the right .zip file depending on your area. If you’re in Australia like myself then this build I9100XWLP8 on the Optus network will be right for you.
Step 2. Inside the firmware you just downloaded is a thing called ODIN, open it.
Step 3. Go to settings and then Applications followed by Development. Once inside there click on Enable for the USB Debugging.
Step 4. Once you’ve done that its time to put your device into Recovery mode. (Do this by holding down the Home Power and Volume up buttons simultaneously.
Step 5. Now click on wipe date/factory reset.
Step 6. Go inside the Advanced Menu and click on Wipe Cache.
Step 7. Now its important to remove your battery and then put it back in again.
Step 8. Power up your device again and hold down Home Power and Volume Down simulatiously putting your device now into download mode.
Step 9. Now back in ODIN click on PDA and find the extracted folder that has all of the downloaded Ice Cream Sandwich files. Once you have located them open it and find the file called .tar.md5 extension. Once found now click start and your done.