The T-Mobile version of the Samsung Galaxy S2 is now can be rooted. One of our trusted android developer slayher over rootzwiki has finally done an awesome job and recently posted a how to root guide of the T-mobile Samsung Galaxy S2 T989. The rooting process is just a bit too easy, by way of - flashing a CWR tar file(ClockWorkMod Recovery) via odin and manually installing an SU zip file (Super User) via the phone's SD card.
Download the ClockworkMod Recovery and Superuser zip files and follow the whole rooting instruction from slayher here.
Here's some screen shots on how to Root the T-Mobile Galaxy S2 device.
1) On Odin put the ClockworkMod Recovery tar file for T-Mobile Galaxy S2 .
3) When ODIN completes the flashing process and once rebooted this time we need to install the SU zip file on the SD card. Copy the SuperUser zip to the SD card.
4) This time we boot the T-Mobile Galaxy S2 into recovery mode by holding both Vol up and Vol down and by hitting the Power button. Once in Recovery mode make a Nandroid backup on the display option.
Then select Install zip from sdcard, choose the superuser zip use the Volume up and Down key and select the SuperUzer.zip to install.