How can I adjust my volume?

[AC Question]

Okay, so my Droid mini's SIM card has been removed and where is has been removed from is actually where my volume buttons are. So today I took my phone out of my pocket and tried to adjust the volume but guess what? My volume button is gone. I have no idea where it went. This was some time during school. I have no idea how to adjust my volume without having to unlock my phone and go to the settings and adjust it. Please if anyone has any kind of advice I'd like to hear it. I'm in desperate need of help because my music is the only thing that keeps me sane during school. That's not a lie....