Howto get fuel out of tank

I have 1990 Jaguar XJ6. Water got into fuel tank due to missing cap. Car briefly ran swhile puttering Now it won't start. I pu contsiner of dry gas in. It did not help.

How can I get the contaminated fuel out of the tank? I tried pushing a plastic siphon tube down the fuel pipe but it won't go down to where the fuel is. I've got 10 gallons of messed up fuel in the tank