Audio Systems: Stereo installation for a 2001 lincoln navigator, premium sound system, kenwood kdc

Question
I bought a 2001 lincoln navigator and the guy put in a kenwood kdc-mp2032 satelite stereo in.  The front speakers dont appear to be working and only the back.  I think he just connected the back speakers with an amp.  The dvd has no sound.  Im wondering when he put in the stereo if he just disconnected a bunch of wires.  Can you tell me if i had to remove the face plate or the wood trim to get to the new radio?  also, do you have some guesses what he might have done that the front speakers and dvd dont play sound? I'd love to have a diagram of the navigator so I could repair everything myself.  I really appreciate you're help.  Thank you very much.  I

Answer
Is the DVD a Ford part, or an after market one? Yes you will have to pull the dash trim to remove the radio, and you will need Ford Radio removal tools to do so. They are cheap and available at most stereo shops and car parts shops.
As for the front speakers, I'm guessing he did not interface with the Ford premium sound system properly, and just ran some of his own speaker wires. This could be a real technical repair, and you may want to get a quote from a pro car audio shop.