As far as I know the screen itself is dumb. You need either the navigation computer or the TV module to drive the screen. And the GPS or TV antenae if you want them operative. In fact you also need a new radio tuner as your new head unit doesn't include one. And all supporting brackets. And the harness .... It can be done, but I don't think it is worth the trouble just for the radio - you won't get a lot more information just because you got the big screen.
Cheers