The root method comes from Rootzwiki – a popular forum for Android hacking/development – in a post from developer slayher where he goes through the different modalities of the whole procedure.
How To Root T-Mobile Galaxy S II On Android 2.3.5 Gingerbread
Download the following files first:
Step 1: Install Samsung Kies on your T-Mobile Galaxy S II. This is to ensure that ODIN can detect your phone with correct drivers in the next step.
Step 2: Launch ODIN v1.85.
Step 3: Turn off your phone, hold Volume Up + Volume Down and plug in your device to a computer via USB cable.
Step 4: Once your device is recognized, select the PDA button from ODIN and navigate to recovery-cwm-hercules.tar. Click on Start. recovery-cwm-hercules.tar will now be flashed to your phone and it will reboot.
Step 5: After rebooting, pull down notification drawer and mount USB storage by tapping connect USB storage.
Step 6: Transfer the su-3.0.5-efgh-signed.zip you downloaded before Step 1 to your SD card.
Step 7: Turn off your phone once again and unplug USB cable. Hold Volume Up + Volume Down and click the Power button.
Step 8: You should boot into ClockworkMod (CWM) Recovery. From here, navigate to backup and storage > backup to take a nandroid backup of your device which may be used in case anything goes wrong.
Step 9: From CWM, navigate to install zip from sd card > choose zip from sdcard > su-3.0.5-efgh-signed.zip
Step 10: Reboot your phone by choosing reboot system option from main menu.
If you followed the steps correctly, your T-Mobile Galaxy S II should now be rooted on Android 2.3.5 Gingerbread.
For queries and help, check out the official thread on Rootzwiki.
Vía | redmondpie.com