Rob, you need the squeeze the sides of the electrical connection, to unlock it. It's fiddly, and the first time you change a globe it takes half an hour, skun knuckles and lots of bad words. The second time is much easier, with far less blood. Let us know if you how you get on, or if more detailed instructions are needed. Have a look at Shiney's "How To" here..... http://ozstoc.com/index.php?topic=3537.0
Have a look at the link below Rob, it should be able to help ST1300 Headlight Bulb ReplacementCheersShiney