You need adapter to input videos in the screen like Vaistech SL2Vu or try to find any kind which will input videos to the screen.
Read more: http://www.clublexus.com/forums/rx-1st-gen-1999-2003/706952-2001-rx-300-no-nav-cpu-video-input-nav-buttons-and-wiring-in-place-2.html#ixzz3toaOaQKg