Sometimes you can shut the engine down manually, SHIFT-R or SHIFT-L for right or left, but if you are going to use the extinguisher, you need to do this:
Click the engine fire light TWICE. Once opens the cover, the other shuts off fuel flow and arms the extinguisher system. SOMETIMES, shutting off the fuel flow will be enough, but if the fire is out of control...hit the Extinguisher pushbutton on the left side of the cockpit to shut down fuel flow and extinguish the flames.
