... ; Shut Down.
After your Mac shuts down, press Shift-Control ... again to turn on your Mac.
If the battery is ... removable:
Shut down your Mac.
Remove the battery. If ... again to turn on your Mac.
Oh yeah, you just mean like a monitor? It’s pretty simple. You might have to get an adapter cable of some sort, depending on the monitor and your laptop. This is how we have our set up at my office, we all have Mac laptops with external monitors.