How to Enable OEM unlocking
Before you can actually unlock your phone, you need to enable the OEM unlocking developer feature in Android.
How to Install Android Tools
Enabling OEM unlocking only makes it possible to unlock the device. In order to actually unlock it, you’re going to need a couple of Android developer tools from Google. These are freely available, and they’re simple to use.
Windows
Ubuntu/Debian Linux
How to Unlock With Fastboot
You’re ready to unlock your phone’s bootloader with the Fastboot tool that you just downloaded. Before you go any further, you should see if your phone requires a code from the manufacturer to unlock it. Here are the instructions for several major phone manufacturers:
LG HTC Motorola Sony Samsung (Only international Samsung phones with an Exynos processor can be unlocked.) Google phones can all be unlocked by default unless you purchased them from a major carrier.
You’ll see a message requesting access on your phone. Check the box to always allow the connection, and confirm. On devices that require a code—or, possibly, some older devices—run this command: You may be asked to confirm. Do so.
