Start by removing 16 allen key bolts. 12 left of the steering wheel and 4 from the right hand side.
Once this is done you should be able to lift the face of the dashboard off in one piece. This is clipped on with a few clips now the allen key bolts have been removed.
You now have access to the screws holding the stereo in place. Undo these.
Disconnect the wiring loom and aerial to release the stereo.