You take out the silver (at least on mine) plastic paneling that goes around the black face plate.
To do this, put a little electrical tape on the screwdriver head to prevent scratching. Then you'll see on the bottom of the silver paneling two slight openings on either side. Stick the screwdriver head in and pry by turning the head of the screwdriver. Then pop the other side the same way.
Then you can pry the top off from each side.
There will be two cords attached to the back of the face plate. I am assuming that one is for the antenna and the other for the speakers etc.
I have a DX also and the guy at Circuit City drilled a hole in the upper right hand side of the plate and then got this ice pick lokking thing that was bent on the end and pulled it out. Seemed to work fine without having to worry about scew driver marks on the silver trim.
Here is a picture of what mine looked like after I installed my Aiwa deck.
I was not able to find a monting kit for mine so I made the plates on both sides out of some metal I got at home depot. I got the plastic part that goes around the deck and below from Circuit City.
The two notches that are on the bottom of the paneling look to be made for a screw driver. But I can see how it'd make somebody hesitant for fear of scratching. However it was -real- easy to pop off. It just seemed like the way it was intended to be.