Contact your Vauxhall main dealer. We, like many forums, have restricted the distribution of radio-codes as a matter of policy. This is because of a, possibly unfair, assumption that those asking for radio codes may have acquired the radio by less than savoury means. Most manufacturers will sell a radio-code for a small fee. Informing users of this policy is better than assuming them to be a criminal! Posts supplying codes will be removed.
Once you get a hold of the code you need you'll need to:
Sit in the car with the radio off and ignition on
Turn the radio on
Press and hold the button markes AS until you hear a beep
The word code and four dashes should now be on the screen
Input the code using buttons 1-4, tapping each one until the correct digit appears on the screen. Repeat for all four digits
Press and hold AS again until a beep is heard and the tuner should start to seek.