Gently separate the front part from the radio unit just far enough until you are able to pull out the flatcable by it's pulling-flap.

Slowly fold down the front keeping in mind the two black sleeved cables still connected.

The two black cables are at the left and right bottom side and are long enough to allow the front to fold down without disconnecting them. But do make sure the folded cable is pulled out from behind the metal plate while folding the front away from the unit.