Rooting Sony Xperia Z

Tools:

1. Flashtool (Download Here or here)
2. Download Xperia Z C660X 10.3.A.0.423 Kernel (Download here or here)
3. Download Xperia Z rooting toolkit and extract (download here or here)
4. Step-4: Xperia Z C660X 10.3.1.A.0.244 kernel (http://d-h.st/Od8)
5.  Step-5: Launch the flashtool by double clicking on the flashtool icon
   

   Note: Those who are first timers, navigate to C:/Flashtool/drivers folder to install Flashtool-drivers. Select and check the box of the device model and Flashmode Drivers such as fast boot,xperia z driver etc

6. Step-6: Connect the Xperia Z to the computer using USB cable. Ensure all drivers are installed properly
7. Step-7: Copy the XperiaZ_C660X_KernelOnly_10.3.A.0.423_Ge­neric_NL.ftf and XperiaZ_C660X_KernelOnly_10.3.1.A.0.244_­BE.ftf to the flashtool/firmwares folder on the computer
8. Step-8: On the flashtool, click on the lighting icon and click flashmode then OK
9. Step-9: A new windows should appear now. At the right sidebar, check Data, Cache, App slog boxes if you wish to wipe the device before flashing. Uncheck all the boxes to remain the data of the device
10. Step-10: At source folder, browse and choose XperiaZ_C660X_KernelOnly_10.3.A.0.423_Ge­neric_NL.ftf in the flashtool/firmwares
11. Step-11: Press flash button to start flashing
12. Step-12: Follow the prompt instructions
First to unplug the USB cable from the phone to disconnect it from the computer Power off the phone Third, enter to Flash Mode on the phone by pressing and holding Volume Down button while connecting the device to the computer using USB cable. The display of the device will still remain blank
13. Step-13: Monitor the Flashtool on the computer. It should continue to run and flash the XperiaZ_C660X_KernelOnly_10.3.A.0.423_Ge­neric_NL.ftf
14. Step-14: Wait for some time until the installation process is completed which will be indicated by a message in flashtool saying Flashing finished
15. Step-15: Reboot the phone
16. Step-16: Connect the phone to the computer in USB Debugging Mode
17. Step-17: On the computer, close the flashtool
18. Step-18: Double click the runme_file extracted from the rooting toolkit (in step-2). This will root the device
19. Step-19: Once rooting is completed, repeat the similar procedure from step-6 to step-15, using the XperiaZ_C660X_KernelOnly_10.3.1.A.0.244_­BE.ftf. This will flash back the stock 10.3.1.A.0.244 kernel to the device

Video Tutorial

http://www.youtube.com/watch?v=10SfxHq7L9c&feature=youtu.be