If your device is unresponsive/frozen there are two methods to force a restart.
1: Soft Reboot: Quickly press the power button 10 times within 3 seconds. This will initiate a reboot of your device. If this doesn't work, please move forward to method number 2.
2: Hard Reboot: Press and hold the power button for 10 seconds. A Hard Reboot is a hardware shutdown, which means the device will turn off all features and force restart.