Deleting an animationclip inside a prefab.

I have a prefab with some animation clips (generated by spriter). I changed the name of my animation, so I want to delete the old, outdated clip. But whenever I right click and click delete on the clip, nothing happens? It's not a seperate file, but rather data inside the prefab file; but I should still be able to delete it, right?

As a side question, is there any way to rearrange or sort the animation clips when viewing them in the animation window (selecting them from the drop-down). I have a lot, so it gets really confusing with them being in seemingly random order.