1. Start by switching off the phone by using the Power button.
2. Next, press and hold Volume Up + Power key for a few seconds.
3. A new menu should appear onscreen. When it does, release held keys.
4. After you do that, choose the Fastboot option by using Volume Up to navigate and Volume Down button to select.
5. Finish by holding down the Volume Up and Power button for a while to see the Fastboot Mode menu.
6. You're done.