Pull out tray below the headunit, then you might need some release clips, can't remember what size, they release the clips holding it in then pull gently and remove wires.
 
plug removal puins or similar under the 1 and scan button. They are in well so pull the tray out and get yur hand under. I have some spare pins around that I can post off to u for next to nothing, if this helps as I have just done mine. O and when he does get it off u will probably need to swap some wires over do make it hold memory.


**edit GRRR Ad u beat me**