As others reported I had a devil of a job to get the cover off, managed in the end with a rubber glove. Went to remove bulb and then glass bulb came away from screw - I was able to remove screw base from unit with a pair of pliers, but an additional screw section came out at the same time - unable to get screw holder back in, or fit new bulb. Changed plenty of bulbs in my time, this seems a flawed design to me

John Baker, October 2011