I’ve had a ton of people ask me how to unroot the T-Mobile Galaxy S2 SGH-T989 so here’s a new stock unrooted ROM you can install over any custom rooted ROM to get back to completely stock Android 2.3.5 ROM.
Step 1. Connect your T-Mobile Galaxy S2 SGH-T989 to your computer via microUSB cable and enable USB storage mode.
Step 2. Download the unrooted stock ROM and put it in your internal storage or external microSD card:
Download Unrooted Stock ROM
Step 3. Reboot into ClockworkMod Recovery(CWM) by holding down Volume Up, Volume Down, and Power button together.
Step 4. As soon as your T-Mobile Galaxy S2 reboots, let go of the Power button.
Step 5. Once in CWM, choose “wipe date/factory reset” and hit the Power button.
Step 6. Choose “Yes”.
Step 7. Choose “install zip from sdcard”.
Step 8. Choose “choose zip from sdcard”.
Step 9. Choose “SGH-T989-UnRoot_ROM_Zedomax.zip”.
Step 10. Choose “Yes”.
Step 11. When installation is complete, pat yourself on the back, your T-Mobile Galaxy S2 SGH-T989 has been completely unrooted.
Step 12. Choose “reboot system now” to reboot.
Step 13. You should encounter the following screen like the day you received your T-Mobile Galaxy S2.
Step 14. You should find that you have all stock apps, SuperUser and root removed.
Step 15. You can also verify ClockworkMod Recovery (CWM) has been replaced back with stock recovery.