Awkward option finger photo, in full effect.

Hold the "Option" button down the entire time that the system is restarting and you will get to the boot options screen.

Being someone more familiar with windows, here is the point where I start worrying about the ramifications of low level operations but, like, whatever, right?

I chose the "Recovery" drive. With the amount of information provided, I figured it was pretty much a crap shoot. Two sentences of text would have probably made it crystal clear. I'm glad I made "The Right Choice (c) 2014."