When I bought my Forester I went to change the Fuel pump to find I had some snapped sender unit bolts which I was really !Removed! off about so all ive done is just seal it just for the vapours.Im not happy with the soloution and want to sort it out.I was thinking of running the fuel really low and using a slow speed drill with all the doors and windows open for ventilation and keep the drill bit oiled up it would take seconds to drill through but I would take the sender out and do that separate away from the tank so there is plenty of air what do you think?

As long as sparcs dont contact with fuel, and you keep it ventilated I would say you should not encounter a problem.