Yes I Can!

How To Root T-Mobile Galaxy S II On Android 2.3.5 Gingerbread

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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.