actually I have 2 questions;

First one is how to remove the head unit ? I have a 2004 Explorer with cd / cassette head unit with the DVD rear system.

I purchased a head unit with the 6 cd but I do not know how to remove the head unit.

Also if my SUV didn't come with a subwoofer, do you think the wiring is there and I can just buy the OEM sub ?

Thanks