Follow this link for main details
http://www.lexls.com/tutorials/audio/headunit.htmlWhen you have removed the 4 bolts holding the radio/ac unit pull the whole unit forward and disconnect the orange multiplug on the ac unit ( push the hinge up and towards the rear of the unit to release)
If you look at each side of the ac unit there are 3 black screws,remove them and then gently prise the sides of the holder to release the ac unit from the bracket.
Now the fun begins! stripping down the ac unit,I have done a few so if you need help let me know.