There should be two big rubber caps for each headlight. Pry them off - your fingernails should be enough - then stick a mirror down there or take a picture with a phone. Yup, sounds stupid and anal, but each bulb is held in place by a wire bracket (bulked up paperclip hinged one side and fits into a catch on the other side), and the bulb has to go in a particular way. Took me bloody ages to get that right! lol
From memory at this point there should be a plug that clips into the back of the plug - it's a bitch to pull out as you have to crook your wrist. (it was sooo much easier with the curren...
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Once unplugged, un-catch the wire frame, pull out the bulb, replace, put everything back (using pic / memory of frame & catch) and that should sort it...