To root your phone, first download the application from the developer's thread at XDA Forums. Once downloaded, start the application and install the Universal Fastboot/ADB drivers. Click the button on the lower right area. Install the drivers, then press the UNLOCK and follow the instructions. Once the phone is unlocked, press ROOT and wait for the operation to complete. At the end of these steps, the phone should be unlocked and rooted.
I personally recommend on using the official way to unlock the bootloader instead of using a custom tool. It's OK for rooting, but not for unlocking the bootloader.