Excuse the stupid question (and the post ride mud) but what tool do I need to remove this crank?

[/url] photo(1) by mcivord, on Flickr[/img]

unscrew the inner bit

What with Al? It doesn’t take an Allen key.

I’ve got some of those, I fit and remove them with an 8mm allen key. Not sure if the inner bit looks knackered on yours? The outer recess looks a bit marked as well…

Your right. I had assumed (as I’m not familiar with it) that it required a special tool but on closer inspection both are damaged. Previous owner must have botched it.
Never mind I’ll just have to destroy it getting it off and replace with new.