Have you had enough playing with your rooted Sony Xperia Z Ultra? Want to unroot your device so you can start everything over? This guide should help you do that. Unrooting and getting the Sony Xperia Z Ultra back to stock is as easy as pie, here’s how:
1. You should have rooted your device using the procedure given here.
2. Your device needs to have at least 70% of battery life left.
3. This only works on Windows based PCs.
1. Flashtool (Download link’s given in the first post)
2. FTF Firmware (Download the appropriate firmware for your device)
1. Download and place both the files onto your Desktop.
2. Double-click on the Flashtool executable and follow the installation instructions.
3. Copy the FTF Firmware file from your Desktop over to the C:/Flashtool/firmwares/ directory on your PC.
4. Turn OFF your device.
5. While your device’s powered OFF, hold down Volume DOWN and plug it in to your PC using the USB cable.
6. Your device is now in Flashmode.
7. Launch the Flashtool program by double-clicking its icon available on your Desktop.
8. Click on Flash icon in the program.
9. It’ll ask you what mode you want to use, choose Flashmode.
10. On the next screen, hit the Flash button and it’ll start flashing the stock firmware on your device.
11. Once the firmware’s been flashed, reboot your device.
12. On your device, head to Menu>>Settings>>Backup & reset and tap on Factory data reset.
13. You’re all done!
Awesome! Your Xperia Z Ultra has been successfully unrooted and restored to stock firmware letting you enjoy the warranty of your device!