how do i empty my fuel tank on ford mondeo diesel?

i have a 02 ford mondeo 2.0 litre tddi and the wife decided to put 20 quids worth of unleaded on top of the 1/4 tank of diesel already in the tank.in her defence she didnt start the car after realising mistake so no damage to seals/injectors, how do i get the 1/2 tank petrol/diesel mix out of the tank other than guzzling any more whilst trying to prime it through pipe?? haynes manual does not show drain plug anywhere on fuel tank!!

Ian
August 2009