*Edit* Febuary 2013, There is a newer ICS stock rom released Janury 2013. Read this guide
Method 2 (my preferred method) Use Odin to install the update. You do not need to be rooted to do this. If you are rooted, you will have to reroot. This is also the easiest method if you are still running Gingerbread or a custom rom.
This is for the T-Mobile Galaxy S2 SGH-T989 phone ONLY
Make sure on your phone USB Debugging is checked in Settings > Developer Options
Make a folder on your PC to put these files. You will need a program like Winrar to extract files.
- Make a sub folder and extract Odin in it.
download this file
. It is the updated stock ICS 4.0.4 rom. The same as you get through Kies. Extract it in your folder. (Thanks to KRZ-2pa at XDA
You should already have Samsung USB drivers on your PC. If you don't, download and install Kies
. It comes with the latest drivers. Close Kies before you start Odin.
1 - Launch Odin by double clicking the Odin3 v1.85 file. Plug your USB cable to your computer but not
2 - Power off your phone. Then hold down both
volume buttons and plug the USB cable into your phone. Press the volume up
button when you see this menu.
You will then go to the download screen.
3 - Wait for the Com port in Odin to turn yellow as in the pic. You do not need to check anything that isn't already. Just be sure that Re-Partition is NOT
checked. It shouldn't be.
4 - Select PDA
in Odin and browse to the stock 4.0.4 file you downloaded and extracted. Select it. Now press Start
and Odin will flash the stock rom. When it is finished you will see a green PASS
in the top section.
5 - Odin should reboot your phone. You should now have the latest ICS on your phone.
Immediately after rebooting, you should do a factory reset in settings > backup and reset, or using the method below.
If you have any problems booting up, or after booting, go to recovery. Power off your phone. Hold both volume buttons
and the power button
at the same time. When the phone vibrates, let go of the power button but keep holding both volume buttons
. In a few seconds you should be in the recovery menu. Use volume buttons to move up/down and power button to select. *if power button doesn't work, use your home key*. Go to wipe data/factory reset
and select it. Next, select format cache partition
. Now select reboot and you should boot normally.