Oil fill plug

[Water Warrior 2]

Just a thought that might work. If you have enough room and filler plug left for the "Easy" crescent wrench get hubby to apply some force to it while you tap the plug downwards with a hammer and stick, punch or whatever to dislodge the darn thing. It was probably screwed in so tight the O-ring is compressed and won't let go. The O-ring was also probably wiped clean of any oil film for lubrication to allow it to turn when needed.