As promised some photos, I've not shown getting the dash apart as there are several excellent guides on here already.
So here is the radio being removed ( I used a couple of cloths to cover trim etc when pulling bits out:
Radio out I plugged int supplied Y cable:
Dice unit plugged in hooked up to my old iPod Mini which will be a semi-permanent fixture in the car as the battery is shot:
And the Audio button displays Extension on screen:
