Flip the midframe over, screen-side-up.

Hook the top edge of your replacement front shell over the top edge of the midframe, aligning the buttons and ports with their cutouts.

Grip the right end of the audio board cable and thread it through its cutout in the midframe and over the motherboard. Use a spudger or tweezers to angle the cable away from the midframe as you thread it.

Ensure the left end of the audio board cable threads over the audio board and doesn't become trapped underneath.