I haven't played w/ the 57xx models yet, so I don't know if they're the same, but if they're at all similar to other Clevo models, it should be fairly straightforward.
On my 8790, there were 4 small tabs at the top of the keyboard. You had to have a small driver or something to slide in between the case and keyboard to push the tabs back; once pushed back, you could pull the keyboard up and out. The only thing is that you'd have to be careful about the keyboard ribbon which is attached to the motherboard. Very flimsy and possibly prone to damage if you're not careful.
While this setup might be different on the 57xx models, I'd hazard a guess that it's not too far removed. Might give it a whirl and see what you can find.
Also, I don't know if it'd help, but if you got some electrical contact cleaner and sprayed it under the space bar (after having removed it from the computer that is), it might clear away any gunk you've got under there. Just a thought.