This guide is thanks to capaxdoli, I have just modified it slightly to make it easier to read
If you use this guide to root your phone please go and thank him here - http://forum.xda-developers.com/show....php?t=1126522
Also please give this page a read it is the basics of rooting and should be considered the starting point for all learning to root - http://forum.xda-developers.com/show....php?t=1125282
Also another thanks should go to Chainfire - For his great work on kernels http://forum.xda-developers.com/show....php?t=1103399
1. Make sure your phone has kies 2 and have it install all the drivers.
2. Connected phone for the first time to computer and kies 2 and it recognized it fine.
3. Make sure Kies 2 is also fully updated.
4. The details of my phone are as follows: (please check what yours are)
Samsung Galaxy S2 i9100 (only use on i9100)
Fireware – 2.3.4 (it will work on all 2.3.x Firmware)
Kernel = XXKI4 (the important bit is the Ki4)
You can find all this info out in Settings – about phone
5. A prayer to My Lord for safe rooting
6. Go to this page and read all, then select the Kernel that is a match to yours – here – http://forum.xda-developers.com/show....php?t=1103399
7. Since I have Ki4, i had chosen to download this file [CF-Root-SGS2_XW_ODD_Ki4-v4.0-CWM4.zip]
8. Downloaded odin3-v1.85.zip here - http://www.mediafire.com/?wezzl287wb9v9hu
Extract and open the file (no installation...gasp!)
Open and run Odin ready to root your phone
Now select PDA and find the kernel that you downloaded and select
9. You might need to extract the kernel to select it in the PDA
10. Put your phone in download mode (press volume down + ok key + power on), a warning about custom OS flashes, press volume up key to continue.
11. You have pressed volume up key and the phone says that it has entered ODIN mode. it also says the following:
a. product name: GT-i9100
b. Custom Binary Download : No
c. current binary : Samsung Official
d. it also shows the android logo (the robot - big size) and says downloading...Do not turn off target !!
12. After this connected the phone to the computer (remember it is in download mode) and the drivers were installed again.
13. Go to Odin and you should see that under ID.com, there is a yellow background box and it says 0:[COM13]. in the message box (lower left corner) it says <ID:0/013> Added!!
14. Make sure the re-partition box is not checked in odin.
15. Clicked the start button...
16. The phone should install your new kernel and then re-boot it should show a yellow exclamation mark when it reboots.
17. That’s it your phone is now rooted –
Please visit these pages to –
See what you can now do with your rooted phone – http://android.stackexchange.com/que...n-from-rooting
How to remove the yellow exclamation mark on when your phone starts - http://forum.xda-developers.com/show....php?t=1103399
This is on the first page only the 2nd post down
For anyone who is intrested if you want to install Ice Cream Sandwhich (ICS) then vist this page here.