This tool will automatically get unlock code and unlock your phone before you flash custom kernel to root and install CWM. If you want to update firmware by SEUS, PC Companion or Update Manager in your phone(OTA). Please relock your bootloader.
Before to do follow these instructions. Please go to Dialpad and press :*#*#7378423#*#* . Go to Service info > Configuration > Rooting Status. Look at Boot loader unlocked allow and if it's show No you cant unlock bootloader. Otherwise, you can unlock your bootloader.