Audi A4 B6 Symphony Cd player replacement

[VAGCOM]

2002 Audi A4.

CD Player: Symphony 6 disc cd changer with built in tape deck.

Im going to undertake replacing the original CD player with a double din DVD player (not sure of what model at the min). Is there things i need to look out for? I Believe the rear speakers are amplified as standard. Whats needed to make the install go as easy as possible?

Any help will be apperciated

Thanks