Settings & Tools > Shutdown > Yes.
This is a soft shutdown and the preferred method of shutdown.
The lid will not open if you use the Shut Down option. If you need to remove the refill, touch Open Lid first, remove the refill, and close the lid. Then the Shut Down button.
Use this method of shutting down only as a last resort. Try shutting down using the Soft Shutdown option first.
Press the silver button on the back of the device for 10 seconds or until spencer screen turns black. Wait a few seconds and press the button again to power on.