Samsung Galaxy S4 Midframe
I had trouble getting the center tab to slide out of the slot. After looking at the other tabs, which came out easily, I noticed that the tabs are not composed of a single piece but are actually two sheets glued together (like two pieces of tape). Somehow the two pieces of tape composing the center tab had come apart, exposing their adhesive surfaces, and sticking to an inner surface. I managed to push them apart enough from the outside with a flathead screwdriver so that I could slide the center tab out. However, the other piece is stuck inside the device.