Careful! This piece is super fragile. It really helps to understand the way the clips work. I struggled for 10 min with not a single un-clip, snapped the plastic frame in 2 places because I didn't understand the clips, and as soon as I figured out how they work the piece was off like a prom dress.
The clips are metal n shapes around the outside of the frame. They need to be pushed away from the center of the device to release the frame. You need to get something in between the plastic and clip to release, a guitar pick is probably too thick. A thin opening device would probably work but I used a razor blade. I'm not sure if these clips are on all of the newer Apple devices, but I've never encountered one before (usually work on android devices.)
I hope this helps prevent someone from having to replace the frame.