The radio does come out without having to remove the whole dash.
You will need a facia plate and removal keys. both can be purchased from halfords. cost about £20-25 all together.
If you have a large radio:
1) you have on each side two holes or screws. (if screws its a small alan key)
2)use the keys to remove the radio.
3) sometimes Vaux use security screws in the back of the org cage. you need a special screw driver for this.
4) remove the org cage. this leaves you a large gap. now place the facia plate over that gap. Now insert the new cd's metal cage. press the thongs in place to hold.
5)connect the new cd up with car's org cables. only goes one way. don't forget the areial. check the cd is working.
6) now push everything in.
Done have fun.
Mishal Chotai, July 2008