siphoning gas from the tank
I'm pretty sure the new filler necks won't allow it. You'll have to drop the tank.
Get under the car, disconnect the fuel line, hook a rubber hose to it, remove the gas cap. You'll get 95% of the gas out by gravity.
You can buylittle hand siphon pumps you squeeze, or a drill powered liquid pump for cheap, once you get the flow going and as long as the end in the tank stays submerged the flow should continue. Otherwise enlist some friends to help lower tank. They aren't astronomically heavy when full of fuel, two people should be able to hold it up and lower it as you slide out just be careful.
Looking for a Used Vibe in your area?
CarGurus has 1,258 nationwide Vibe listings starting at $1,399.
Search Pontiac Vibe Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Pontiac Vibe Experts