2.51/64b : where did 'edit actions' go?

I've just upgraded from 2.42/32 on XP to 2.51 on 7/64.
I see that actions have moved to their own tab. If this means more users see/use them, that's great!
However... I can't find any kind of edit/new/delete button.
I did a forum search, didn't see any chatter about this, so I'm probably being extra thick (sorry) but could someone point me at that functionality?

PS: I moved my old actions over by copying the MTA files in data\actions over.

It's the first entry from the actions menu or the toolbar button :mt_act: