If you’ve updated your Samsung Galaxy S2 GT-I9100 with the official Samsung-released firmware for Android 2.3.6 Gingerbread build XWKL1 and have lost your root access along the way, there’s a way for you to get it back.

Firmware XWKL1 for the Galaxy S2, said to be an incremental firmware update officially from Samsung, reportedly provides better battery life than earlier firmware updates.  For this reason, many folks have updated their Galaxy S2 to the said firmware and took an extra step: rooting the phone in order to further customize it.

In this guide, you will learn how to root your Samsung Galaxy S2 GT-I9100 after updating it to firmware XWKL1 of Android 2.3.6 Gingerbread.

Requirements

• Samsung Galaxy S2 GT-I9100 with Android 2.3.6 Gingerbread firmware XWKL1 installed
• Back up all your personal phone data (e.g., contacts, SMS, files, photos, Internet settings, MMS, etc.).  Do not use Samsung KIES in creating a back-up. Your rooted phone may be incompatible with Samsung KIES.
• Charge your battery to at least 60% power (full charge recommended) to keep your device running throughout the rooting procedure.
• Disable all system tools such as Samsung KIES, firewall programs, and antivirus software. These tools might affect or hinder the rooting process on your mobile device.

Warnings

These instructions are for the Samsung Galaxy S2 GT-I9100.  Do not try these on another variant of the Galaxy S2 (such as the GT-I9100G).

Do not attempt to use this guide if your Galaxy S2 is not running Android 2.3.6 Gingerbread firmware version XWKL1.  Otherwise, you could brick your phone.

We will not be held responsible for any damage arising from the use of this rooting instructions. Root your device at your own risk.

Instructions

1. Get the XWKL1 root package from here.
2. Extract the RAR archive’s contents into a folder on your computer.  Use WinRAR or other RAR extraction software.
3. Go to the folder containing the extracted files and launch the Odin3_v1.0 program.
4. Switch off your Samsung Galaxy S2.
5. Press and hold the Volume Down key and Home button (middle key) simultaneously, while tapping the Power button to reboot your phone into Download Mode.
6. Once in download mode, connect your mobile device to the computer using USB cable.
7. Go back to Odin3 and click the “PDA” tab. From there, select the file “CF-Root-SGS2_XW_INU_KL1-v5.0-CWM5.tar” you got from the extracted files.
8. Under Option in Odin3, make sure only “Auto Reboot” and “F. Reset Time” are checked.  Leave the other options unchecked.
9. Click the “Start” button in Odin3 to begin the rooting process. This will take a few minutes.
10. When your phone has been successfully rooted, your mobile device will automatically reboot.
11. Disconnect your phone from the computer once the homescreen appears on your phone.
12. Switch off your mobile phone.
13. Reboot your mobile device into Recovery Mode by pressing the Volume Up key, Home key (middle button), and Power button simultaneously.
14. While in Recovery mode, select “Wipe data/factory reset” and confirm the action on the next screen.
15. Select “Wipe Cache partition” and confirm the action on the next screen.
16. Go back to the main menu and select “reboot system now” to restart your phone.

Congratulations! You have successfully rooted your Samsung Galaxy S2 I9100 running firmware XWKL1 of Android 2.3.6 Gingerbread. You will also notice that ClockworkMod Recovery and Superuser app have been installed on your phone (a reliable indicator if you were successful in rooting your mobile device).