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BabyEagle9mm posted on r/askmechanics3w
Get some fuel line at a parts store that attaches the fuel return line from the fuel pressure regulator. It is the larger one in this picture. Probably 3/8", maybe 5/16" and a hose clamp. https://a.co/d/049CGNj9 Put the other end in a gallon jug and turn the ignition on, the fuel pump will run approximately 3 seconds. Continue turning the switch off and back on until you fill the jug. The stale fuel when mixed a gallon or two to every full tank on the other vehicle will not cause any issues to that vehicle.