After that the news can be grim. Let the battery run out if you can't get to the battery.
I own a Toshiba Satelite P55-A5312 with an intel core i5, a few days ago I turned of the computer but when I tried to turned on again the "Shutting down" screen was (and is) still there and even if I press the power button and hold it it doesn't work. I've seen a couple forum discussions where other people experienced similar problems and fixed them by removing the battery and putting it back on again, but my Toshiba's battery cannot be removed that easily. What can I do to fix this problem?