Hi,
I hate those little spring clips - whereas I only dislike allen key grub screws (Why not square in stead of hexagonal?!).
You'll need some more tools I'm afraid. If you're working at the tiny end of the spectrum you need tiny tools.
There should be a couple of tiny slots for an equally tiny screwdriver flat to go in - but I suggest you prise it off inside a clear plastic bag if you don't want to be grubbing around in the far corners of the floor in search of the escaped part!
Good luck!