Hi, maybe a dumb question, but I have the standard and extended length back rivet sets from Cleaveland tool, and the plastic sleeve on the standard set is split. It?s non usable because it is allowing the rivet tail to drift off the set and is only setting half the rivet tail. I?m trying to remove the sleeve to replace it, but can?t figure out how to remove the pins that ride in the slots on each side of the sleeve. They don?t appear to be hex ends and they don?t punch out. Are these even removable, or am I just too dumb to figure it out? Thanks.