How To Root Sony Xperia Z Ultra

1. Before You Begin:

Working for Sony Xperia Z Ultra 510 & 493 LTE Firmwares with Unlocked Bootloader
Install Custom Recovery From Here
Windows-based computer or laptop.
Download Sony Xperia Z Ultra USB driver for Windows and install in your computer.
Skip this step if you have installed the Sony Companion.
Enable USB Debugging on your device.
Make sure your phone is charged to 60% 80% to avoid battery blackout and interruption during this tutorial.
We recommend you make a backup on your data and media files before the tutorial.

Unlock bootloader of your device first.
Install CWM and TWRP custom recovery in your device first.Click Here
Download the Pre-rooted stock firmware file.
Transfer the pre-rooted firmware to your device's external storage.
Now Press Power+Volume Up button until Sony Logo to boot into recovery mode (Make sure custom recovery is installed Click Here if not installed).
Now you are in CWM custom recovery.
Select Wipe Data/Factory Reset and select yes to confirm then Wipe Cache Partition and select yes to confirm and at last Wipe Dalvik Cache from advanced menu and select yes to confirm.
Now go back to Recovery Home and select install zip from sd card then select choose zip from internal sdcard.
Select the download and transfered pre-rooted stock firmware and select yes to confirm the installation.
After successful installation, go back to recovery menu.
Select reboot system now.

Congrats!!! your Sony Xperia Z Ultra is rooted now...Enjoy :D