There's a standard wire clip to release and then the headlamp bulb can be removed.
Don't touch the glass of a new bulb or you'll shorten the bulb's life drastically.
Re-assembly is the reverse of disassembly. Re-connect the electrical socket while there's still space to do it. You'll almost certainly have the same sort of trouble properly locating the assembly before it will slot back into place. Basically, the bottom lugs don't want to locate back into the slots. You know you need to lift the headlight unit but there's not enough space at the top to do it. A prolonged bit of jiggling while easing the left hand side bodywork will eventually do the trick.
I guess if you've done a fair amount of headlamp removal, you'll have found the right way to line it up to slot back in place straight away.
And that’s it.
NOTE ADDED LATER (10/11/14):
Jacob Hassing has kindly provided some feedback and a photo. He found that it was necessary to remove FOUR bolts to free the headlamp assembly. Maybe a slightly different version for a different market.