A way to do it outside of terminal is:
# Press the icon in top left of screen
# Click Shutdown
# Turn on the Mac while holding down the Command-Option-P-R keys until you hear the second start-up sound.
# Release the Command-Option-P-R keys.
# or
## Press the icon in top left of screen
## Click Shutdown
## Disconnect the MagSafe power adapter from the computer
## Remove the battery
## Press and hold the power button for 5 seconds
## Release the power button
## Reconnect the battery and MagSafe power adapter
## Press the power button to turn on the computer
# or
## Press the icon in top left of screen
## Click Shutdown
## Plug in the MagSafe or USB-C power adapter to a power source and to your computer.
## On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
## Release all the keys and the power button at the same time.
## Press the power button to turn on the Mac laptop.
# IF those dont work comment on one of my posts and I will give more methods