This posts lists the steps to enter the Android Recovery screen.
Press & hold the Volume down button. While holding Volume down, press & hold the Power button until the device turns on. You'll see the word "Start" with an arrow around it.
Press the Volume down button until you highlight "Recovery mode."
Press the Power button to start recovery mode. You'll see an image of an Android robot with a red exclamation mark.
Press & hold the Power button. While holding Power, press the Volume up button once. Then release Power.
Android Recovery Screen