yes new casing is needed as the original player is kind of bonded together. But repaint and silicon i dun think so.....
Most of the audio shop got sell and they can do it for u. But honestly speaking, DIY really hard....as u need to open the radio panel, button panel above the player, centre console(where ur power window switch and hand brake, and the gear selector located) Need to strip off quite alot of thingy....when i see the audio shop worker strip my car....l was so heartache....new car woh...even they really take care and gentle