Woah woah WOAH!
If you read the manual for your diesel Astra, you will see a very important message regarding repressurising the fuel system. It only applies to the diesel one, so I'm sure it's not just there to drum up business for the main dealers.
There must be a good couple of litres of fuel in the lines, pump etc. at any one time, so there is no way you could just turn the engine over a few times to pass it through. So, you'll need to empty it all out, and repressurise the fuel system.
If I were you, I'd take it to a main dealer. Cheaper than a new fuel pump, surely?