Empty cases? Take pliers, insert into empty case, pull directly out from the "clip" without applying any pressure upward or downward that will bend clip.
Loaded ammo? With fingers pull round directly out from the "clip" so as not to distort it up or down.
Question is, do you wish to save the clips, either so-called "half moon" 3 rounders or "full moon" six rounders?
If you plan on using them again, then a demooning tool might be in order but is not necessary.