Why didn't VX do this as standard?? Well now you can remedy the faux pas with this excellent 'How To from BasilD
Astra-Sport Disclaimer - Please note that this is a guide only and Astra-Sport take NO responsibility for any damaged caused to yourself or vehicle whilst using this guide. If you are unsure how to do something leave it to the professionals. Your Insurance and warranty might be invalidated if this modification is done.
A link has been placed in the Tech Section, so you'll always be able to find it