[john walker's workshop]

A crowfoot tool and a big screwdriver behind it for leverage will move the #6 shaft enough to get a screwdriver in the groove to continue moving it outward. No need to take the cooler off. For the keeper install, Grease in the grooves and stick one on your finger with some thick grease and carefully put it in place, rotate it 180 and do the other one. Thick grease like point grease or optimoly, etc. Never used anything but sticky fingers to do it in the car. Never used air pressure either, the stem seal keeps the valve from moving, and if it does, just pull it back up.