Touchscreen broken, alarm clock won't stop ringing

[AC Question]

So last week my screen broke and touch doesn't work. I have my alarm clock set so that it never stops ringing unless I turn it off. My phone has been ringing for about 24h now, and since I am planning to get it fixed after school, I have to somehow turn it off before doing so. Any suggestions how? (I can't turn the phone off and it won't die soon because it has great battery)

 

[B. Diddy]

Welcome to Android Central! Which phone? You can always force a shutdown by pressing and holding the Power button for about 10-15 seconds (or, if it's a Samsung, Power and Vol Down).