Am I the only one who hates these things!? I've had to remove six of them three times now in connection with a lighting project and all I can say is first, they're a pain in the ass and second, I broke one today.
Here's how they work. Sometimes they actually do, sometimes they don't. Seems like things go astray during the removal process when they don't pop right out and you need to pry at them with a screw driver.
Oh, did I mention that they cost $1.25 each?
Nothing should be held together with fasteners of this design.