HELP!!!!!!!

Faithful followers, I have a challenge for you!  Come a little closer so you can hear properly.  That's it... little closer..... NO!! Too close! Back off a little... perfect. Okay, I have an Incase for my iPod.   I CAN"T REMOVE IT!!!!! My iPod is a Nano chromatic I got about three years ago.  (4th or 5th gen, I can't remember.)  The Incase is one of those hard shell ones that snaps onto the iPod and looks like this: 

The arrow is pointing to the slot where I seem to recall the little paper that came with this case said to pry it open using a coin.   I tried this but it was flexing weirdly and i was afraid it would break.  I couldn't find the paper it came with, and the internet was completely useless-- I NEED YOUR HELP!!!! HOW DO YOU OPEN A CASE LIKE THIS??? I need to get it off because my iPod is getting filthy under there and the screen is a bit hard to see now.  PLEASE help me!!!!  Post comments with ideas for opening or information!!!