Bootloader unlockers/lockers from recovery are here.
Easy method to unlock & relock Optimus G bootloader.
Good things about these zips:
1. No running OS is needed.
2. You don't have to be on lg stock roms.
3. Work much faster & easier. Less than a minute.
4. You will still have custom recovery after locking your bl.
How to use?
Using bumped recovery, flash them like other zips in recovery.
Don't have recovery?
Flash a bumped recovery img (inside of the attached zips) with an app like Flashify or Kernel Adiutor or etc.
Note: BL unlockers flash unlocked bootloader + Philz/CWM recovery. Booting up on unlocked BL needs unlocked kernel.
So in stock roms, don't forget to flash an unlocked kernel, like unlocked stock kernel or solid kernel or etc...
Anyway in case of any problem, there is no worry because you can always access to Philz touch(for E975) or CWM(for other variants) recovery.
I could only test E975 ones. Other variants unlockers must also work. But you are the testers...
Mirror links (files folder):