Aung Thu: How to Root Galaxy S2 (International Version)

First, download and install the software Kies on your computer, which will install the necessary drivers for the phone.
Download Kies
Download the CF-Root 5.6 [Updated]
Download CF-Root-SGS2_XX_OXA_LQ5-v5.6-CWM5.zip|
Extract the CF-Root-SGS2_XX_OXA_LQ5-v5.6-CWM5.zip file to obtain a file named CF-Root-SGS2_XX_OXA_LQ5-v5.6-CWM5.tar. It’s important you get a this file with .tar extension. If you get files like recovery.img and cache.img, you’ve knowingly or unknowingly extracted the zip twice, which means the .tar got extracted too. In that scenario, use 7-zip free software to extract the .zip file, this should get you .tar file simple and easy.
Download the Odin. If you are new to this, know that Odin is what is used to flash stuff – firmwares, kernels, etc. – on Samsung phones. We’ll use Odin to flash the .tar file of CF-Root you just obtained step 3 above.
Download Odin3 v3.04 | Filename: Odin3_v3.04.zip [It’s all new Odin with refreshed looks, btw. Cool.]
Extract the contents of the Odin3_v3.04.zip file to a folder to get bunch of files: Odin3 v3.04.exe, Odin3.ini, tmax.dll and zlib.dll. Don’t delete any file. If you have not turned on ‘show system files’ option in windows you might not see some files. But you’ll see the Odin3 v3.04.exe anyway, and that’s all we need.
Now, turn off your Galaxy S2, i9100. Wait for some 8-9 seconds.
Then, the Galaxy S2 into download mode. To do so, press and hold these keys together: Volume Down + Home + Power till the screen turns on. Then press Volume Up then to enter download mode.
Run Odin — double-click the Odin3 v3.04.exe file obtained you extracted in step 5 above.
Important! Connect your phone to PC now. You should get the message “Added !!” under Odin’s message box in the bottom left.
If you don’t get this message, make sure you installed drivers correctly (using Kies or directly) as given in step 1. If it still doesn’t work, try changing to another USB port on the computer and also use the USB ports on the back if you have a desktop PC.
If you don’t see Added!! message, the rest of guide is of no use to you. So, get it first.
Click on the PDA button in Odin, then browse to and select the CF-Root-SGS2_XX_OXA_LQ5-v5.6-CWM5.tar file obtained in step 3 above.
Important! Do not make any other changes in Odin except selecting the required files as given in step 10. Leave all other options as they are. And make sure Re-Partition checkbox is not selected.
You Odin’s screen should look like this one below (this is old screenshot, so it features older version cf-root, but don’t worry about that):
Click on Start to start flashing the CF-Root and root your GS2 with just one-click. When the flashing is complete, and is successful, you’ll get a PASS message (with green background) in the left-most box at the very top of the Odin. And the phone will automatically reboot. When you see the Samsung logo, you can safely unplug the cable.
IMPORTANT Note: If ODIN gets stuck on setup connection or at any stage of this process after you’ve hit the Start button, and doesn’t seem to be doing anything, or if upon completion of the process you get a FAIL message (with red background) in ODIN, do this: disconnect the phone from the PC, close ODIN, remove battery for 4-5 seconds, re-insert it, turn phone on in Download mode again, and do the procedure again from Step 8.
That’s it. You’ve successfully rooted your Galaxy S2 i9100, and have installed clockworkmod recovery too. When the phone boots up, check out the CWM Manager app, and the SuperSU app, the latter will manage root access and permissions on your phone.
If you experience any problems, let us know in comments below. We’ll try our best to help you as quickly as we can. And do share this guide with people you think it will be useful to.