Once the battery and the motherboard have been removed, the inner framework can easily be lifted up off the LCD assembly.

Good news everyone! The second Wi-Fi antenna is held in place by mild adhesive, so it comes out fairly easily.

In addition to housing the Wi-Fi antenna, the inner framework is home to the ambient light sensor/microphone/front-facing camera ribbon cable and headphone jack ribbon cable. Check them out:

Ambient light sensor

MD v1.2 Microphone