How do you drain petrol from a diesel 2004 reg corsa?

I have the same problem. Today I absent mindedly put petrol into my diesel corsa (also a 2004 model) I was quoted £250 from some company the RAC put me in touch with. Sod that! (There are cheaper ones out there).

I got the RAC to tow me home. Tomorrow I will disconnect the fuel line under the bonnet where it goes into the filter. Connect a bit of pipe to the fuel line and turn on the ignition (not cranking the engine). I think there is a submerged pump in the fuel tank. I hope that this will empty the tank into some jerry cans. Then I will flush some clean diesel through the system. Fill the tank up and keep it topped up for a few weeks. I hope this will dilute the petrol enough not to matter. One problem is what to do with 40 liters of contaminated petrol. Start a big fire :-)?