Flip the phone open with the back side still facing you.

Grasping the phone on the sides, use your fingers to push up on the keypad and motherboard until they release from the phone casing.

When you do this the plastic camera button will pop out. It is not directly attached to anything. Make sure to save it for reassembly because it must be placed back on its tab at the side with the camera icon is facing right side up to work correctly