There's supposed to be a spring-loaded clip in one of the slots on the heads, push that in with something somewhat narrow and poky and you should be able to twist the "cup" off like a bayonet mount.
I will try it . probably you areright because one of the three clip is 2-3 mm pop up from the capsule. I do not have the special key and do not want damage the hole. I will find something to fit to force it. Thanks again
