1. Go to your Settings and scroll down to System and tap About Phone.
  2. Tap on the Build number seven times until the dialog box says "you are now a developer."
  3. Go back to the System menu and you should find a new option called Developer options.
  4. Make sure that the developer options are turned on and that USB debugging is on.
  5. While in Developer options, turn on OEM unlocking.
  6. Plug your device into your computer and click "OK" on the dialog box asking you to Allow USB debugging while connected to the computer. You can also select to always allow access on that computer.