Here you can buy the maintenance kit: http://ebay.us/q2bWlb
This video will show you how to change oil and oil filter on OpelVauxhall Astra H 1.7 CDTI (produced between 2005 and 2009) with an oil and filter kit found on eBay.
These instructions suit many diesel cars.
You'll learn to work on your car and save money!