I just took one out of mine. on the left and right hand side of the stereo are 2 little plastic covers that need to be prised off. You should then see 2 holes each side. Stick a small screw driver in each one to push the metal clips aside and it should slide out. Its quite fiddly and if you are replacing the stereo, you will find it easier to prise the front of the whole thing off so you can see what metal clips you need to be moving aside.
Chris
February 2008