1. Press Power button until the phone turns off.

2. Next, press and hold these buttons simultaneously: Volume Up & Power. Release them after the Boot Mode pops on-screen.

3. Select Recovery by using Volume buttons. When the Android icon pops on-screen, press and hold the Power button. 
4. Press Volume Up button once to enter Recovery Mode.

5. Operate here by using Volume to navigate the options and Power to confirm.