I picked up a replacement rear view mirror (like this:
http://busdepot.com/details.jsp?partnumber=113857511L) but I can't
seem to figure out how to get the old one off. Does anybody know how
it comes off?

I scoured the bentley manual with no success finding anything about
removing that mirror. It feels like I'd just slide it up and it'd pop
out somehow but I felt like I was trying too hard when I attempted
that method earlier today.

Thanks!
Zach