Easiest and quickest way is to remove and fill fuel filter with clean diesel, then loosen a couple of injectors and crank until diesel is pumped through these (beware of killing battery). Then replace them, and start engine. Might run on two for a few seconds, but should then self bleed. If it's a company car, I would grit your teeth and confess. Or say the gauge was reading a quarter full - you might get away with it in a Vauxhall.
Andrew McLaren, March 2005