Ah, didn't realise it was a diesel. What makes you think it needs replacing as the diesel pumps are a lotmore expensive than the petrol. For a new pump you're looking around £1300, or a recon for £800ish plus a refundable surcharge when the broken pump is sent off or a second hand one for £400ish but there's no guarantee that a second hand one will be any better. Plus labour of about £160 if we do it. According to this post
vauxhall quoted someone £1680 plus vat and £375 plus vat for labour and that was in 2008.
Are you totally sure it needs a new pump? As far as we know this zafira models pump isnt programmed to the ECU so that shouldn't be a problem.