Nakamichi mb75 6 Disc CD Changer/Player mechanism issue

Hi I have this nakamichi mb75 and there is one piece is like same size like the one the holds the cd but that one is plastic and this one METALIC fell off I bought it like this im trying to see where exactly is the position of this metallic disc I've watched an YouTube video but quality of video is nit that great and I can figure where this it goes in the mechanism.ive downloaded the schematic but the mechanism its not shown disassembled.please help me.thank you