I aways removed the valve when the diapram went bad, "you put your finger over the hole in the middle of the small plate and you had vacume" you unbolted it from the manifold and used a large allen wrench and removed the swivel nut from the intake manifold , yes it takes a allen wrench on the inside , then you remove the nylon part that screws into the top of the valve and use that as a plug , same threads , the small 1/4 hose you plug at the carb , it was in a vent part of the carb , not needed , car will run the same and not have that high idell anymore ,