I stupidly put unleaded fuel into my p-reg 1.8 diesel fiesta van, I've spent a few hours trying to figure out how to drain the fuel tank to no avail and there seems to be an anti syphoning device so I can't do that. Any tips would be greatly appreciated (feel free to tell me how much of a moron i am!).

go underneath the vehicle and disconnect one the hoses connected to the fuel tank and then suck it out from there or else disconnect the fuel filter and suck the fuel out the pipes in both directions.

go underneath the vehicle and disconnect one the hoses connected to the fuel tank and then suck it out from there or else disconnect the fuel filter and suck the fuel out the pipes in both directions.
I agree. If necessary, you may have to emove the tank to drain it. But all that contaminated fuel must be removed. Don't start the engine until you do so, or severe fuel injection system damage might result.