There is a tool, but it breaks easily if you use it a lot.

Go and buy a cheap jewelers' screwdriver set and grind the tip so it is thin enough to fit in the cavity where the tab on the metal clip is. Simply push the tab down with the screwdriver, and pull it out. In a pinch I use a nail - much quicker than using the tool designed to do the job !

That's right.. my tool bent over on the first go. Used a tiny screwdriver instead