How do you reset a radio on an Opel Corsa after the battery has been replaced?

You'll need the radio code to do this. When you reconnect the battery the radio will display the Word 'code' when switched on. The code should have been recorded in the vehicle handbook by the dealer, you enter this four digit number by using the preset keys. If you get it wrong, you will probably have three attempts. The radio will then lock out for around an hour or so.

If you have lost the code you can visit the radio manufacturers website and ask for help - you will need to prove ownership of the vehicle, or a visit to the local Opel dealer may help.