Press and hold the Power button
Tap Restart or Reboot
If Restart is not shown, tap Power off
Wait for the phone to turn off
Press and hold the Power button again
Release when the Android logo appears
If the phone is frozen, press and hold Power and Volume Down together for 10 to 20 seconds
If that does not work, press and hold Power and Volume Up together for 10 to 20 seconds
If the phone has a removable battery, remove it, wait a few seconds, reinsert it, and turn the phone on
If the phone still does not restart, charge it for a few minutes and try again