5.3 Intake manifold vaccuum plug removal

[deelli]

Trying to remove the plug from the back of the intake manifold on a 2004 5.3, it's the plug with the red lock ring. I've heard that you should pull the red ring back and the plug would come out...I did that but the plug will not come out. Could someone tell me if this is the correct procedure.
Thanks

[CHEVROLADE]

push in the red ring then pull plug

[deelli]

Thanks