To replace the earpiece speaker, it is easiest to install the speaker and bracket together:

Place the earpiece speaker bracket over the speaker so that it fits snugly in its housing.

Slide the left hook of the bracket into the notch above the top left corner of the front facing camera.

Rotate the bracket so it lays flat on the rear case, aligning the two screw holes. Press the bracket into place, ensuring the hook on the right side of the metal bracket latches onto the display.