How to Disassemble A Lenovo 3000 C300 All-In-One Desktop?

I need to replace the hard drive into this compute. I can't figure out how to take this thing apart. I unscrewed the screws from the back of the monitor I have tried to pry it open but I do not want to chip or bend the plastic or damage it. There has to be a simple way to do this. Any help would be greatly appreciated. Thank you!

NOTE: I have tried to look up guides on google and Lenovo.com, but the maintenance manual i found only gives instructions about how to replace the keyboard, mouse or power cable (dooh, just unplugging them)