Firstly DOH! Secondly well done for NOT starting the car that has just saved you a lot of hassle and money I don't know much about stilo fuel tanks but there must be away of draining the petrol out? Perhaps where the fuel filter is? ( if it's next to the tank that is ) but if your a novice, i'ld say your best bet will be a garage? they'll enjoy better luck with it up on a ramp and maybe a pump?

Usual cause of action is car up in thr air filler neck removed from tank then a jiggle siphon used to decanting the fuel into suitable containers..... for safe disposal. Then tank off to drain last trace...

Replace tank then fill

Next fuel filter inlet pipe off. And into container and cycle ignition on and off that buzz you hear when turning key to mar is the fuel pump priming so flush till its pure derv

Then put back on and pray it works

Obviously extreme care needed if you diy petrol obviously burns very well safety first and all that

There is a company online, that comes out and sucks it out your tank for you.

http://www.fueldrainer.co.uk/

http://www.fuel-doctor.co.uk/?campaign=nationwidenew

http://www.drfuel.co.uk/?gclid=CNfupZuK5bECFYQXzQodLFAALg

i would give them a call and see what they say

i'd have a company do it if I were you. its not worth the risk or creating a large fiery explosion with you in the middle due to the fumes from the decanting method PLUS, and i know this from experience, it will take you AGES to wiggle it out into suitable containers.

a company will recover the fuel and sort the tank out too.

Just reminded me of when I used to be a mechanic many years ago, we used to do a fuel extraction service and when we emptied a full tank of petrol, the boss used to let us have it. I'ld put in in my old panda.... Used to stutter occasionally but my dad used to say that the diesel would clear the carb jets out

Thank you guys for all your suggestions. i was kinda hoping for a 'just siphon it out' suggestion but it sounds much complicated so i got in touch with my local garage who has quoted me £122 all in to sort it for me.

Bet you won't make that mistake again!

depending how much you put in, ive done it, i put about £10 worth in the car when i first got her.
i stopped when realised and just made sure i topped it up with diesel, the car was smokey for that tank and a bit low on power.
i ran the tank down to 1/2 way and topped up again with diesel and ran the car normally.
I then replaced the fuel filter as i was worried the petrol would bring up crud.
i had no adverse affects from petrol and the car has done another 80k since.
just low on power and smokey