>>For Android 8 and above use this instruction HERE<<

Video tutorial

Click here to get bootloader unlock code (This service is not free)

Bootloader unlock process (free)

NOTE: DC-unlocker won't be able to assist with any problems that arise while using this method

Download ADB toolkit

Install it, then locate “fastboot.exe” file in installation directory

Turn off phone. Press and hold Vol- and Power buttons to enter fastboot mode

Connect phone to pc via usb cable

Click “windows” + “R” button, type in “cmd” and click “OK”, command window will open

In command window enter directory of where ADB toolkit is installed and check that the device is connected to computer properly. To do so, enter fastboot devices, and press Enter, if a message such as 156b267e fastboot is displayed, the connection is set up properly

Type in unlocking command - fastboot oem unlock password, for example, fastboot oem unlock 1531461291861883

After entering the unlock code your device restarts and sets to standby mode

If you receive an error "Command not allowed" it means you need to enable OEM unlock on your phone for bootloader unlock, how to do it check here

OR

Disable all protection that is enabled on your phone like finger print, patternt lock and phone finder, how to disable phone finder can check here

To check bootloader's lock status simply repeat detection of the phone by DC-Unlocker or enter “fastboot oem get-bootinfo” in command window