Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.
Try this http://forums.justcommodores.com.au/attachment.php?attachmentid=2360&d=1117703288 its for the module if the buttons arent in your car dont run the wires for them.
Mate I got mine installed for $50. Worst comes to worst, that's all you'll be up for. Any stereo shop should be able to do it for you. By all means, have a crack at it yourself though!