Fuel leak problems

[5000fingers]

Last week I replaced the fuel filter on my 2011 OB, and checked very carefully for leaks after reassembly, no problems with the car running. Well, yesterday I filled up the tank and drove home. This morning I went outside and found a puddle of gas under the tank, and still dripping. Turns out the gas is leaking from the rubber gasket – which I thought I installed and torqued correctly. The gasket looked to be in good shape, so I didn't replace it. So just now, I tightened the 8mm nuts even further, but it's still leaking. So, off to the dealer to buy a new gasket I suppose, or maybe I did something wrong somehow, I don't know. It seems like a no-brainer, it can only go on one way. 

The question is what I do now, with a full tank of gas that is leaking out the fuel filter gasket. And I presume a lot of it will come gushing out all over if I take open things up again. In the old days I would just siphon a few gallons out and make the repair, but I know modern cars have rollover valves and other devices that prevent siphoning. 

So, please advise: 1. How to deal with the full fuel tank in order to open up the fuel pump/filter assembly again. What's the best way to stop the leaking, and do the repair without pouring fuel everywhere? If I jack up the passenger side, would that allow me to take off the fuel filter assembly without gas spilling out?

And: 2. What might have gone wrong with my repair?

Edited August 2, 2023 by 5000fingers