2 I did crack that hard plastic band in two spots on the top left corner of my Nexus 7 (opposite the camera). On spot a tiny piece broke out, but the band is still continuous at the glass edge. Around the corner, the band actually appears to have broken in two. If I rub my finger there, I can begin to peel it up. I hope my case will keep it protected.
1 If you look closely, you'll see that at the edge of the glossy, black screen there is a glossy, black, 1mm hard plastic band going all the way around the screen. This provides the beveling on the edge of the screen. Around that is the dull, black plastic case. Insert your spunger or fingernail between these two plastic bands. It is easiest to do near the middle both of the long sides. Gently slide up toward the corners popping each little snap. When you get near the corner, keep one fingernail/spunger in the gap you've created on the side, near the corner, then use another nail/spunger to go around the corner. Be careful here. This is the easiest place to damage.
Once the corners have popped, the end/short top edge is easy. The bottom edge is different since the micro-USB port is also there. I did not pry it open but lifted the other three sides and just slid the screen out from that end. I inserted the USB end first also when reassembling, snapping the other edges then corners in afterward.