I’ve put it upon myself to update my car’s sound system this summer. This came about after my brother totaled his car and I was left with his 2 12 inch Alpine sub woofers and still in great condition. I was doing some reasearch on the matter and apperently there are quite a few things that need to be done first. It isn’t required to remove the factory radio that came with the car, but I figure “why not” might as well do it big if I’m going to do anything at all. I drive a 2008 Ford Focus and this is how you remove the radio:
1) You want to start off by pulling the e-brake all the way up as far as you can. I also found it helps to put the key in the ignition (you don’t need to start it) and put your automatic transmission into D or L. This will just make it easier when you pull off the plastic that surround it.
2). Open the middle storage compartment and pry the plastic up with a flathead screwdriver (see picture below).

3) Once you remove the center plastic that surrounds the e-brake and shift stick you need to remove the 2 screws that secure the bottom of the radio unit into place (please see the below picture).

4) Using a flathead screwdriver pry the plastic plate on the passenger side (where the airbag is located). This won’t come all the way off, as there’s a screw keeping it from doing so. You should be able to to get it off enough to be able to remove the radio.

5) Remove the two screws holding the plastic that surrounds the steering wheel.

6) Lower the steering wheel all the way and remove this plastic.

7) Remove the vents above the top of the radio dash unit.

8) Remove the two screws holding the radio in place.

9) Starting from the bottom begin to pull the dash unit out.

I hope this helps for anyone who wants to try this. I apologize for not knowing technical words for things or for my lack of explanations. I hope the pictures speak pretty much for themselves. Good luck!