2838 motors internals --------------------- Photos and opening procedure courtesy of Jochem Wildenberg. As you can see tell from the pictures I managed to open it up, which appeared to be less difficult than I thought. I carefully pried it open with a fairly small screwdriver, starting at the back, and then working my way to the front along one side. This way I created a slot just high enough to fit the blade of the srewdriver. Then I worked my way from back to front along this side again, putting the screwdriver in the slot between each pair of 'fingers' of the upper casing carefully using the screwdriver as a lever. After this you only need to prie the screwdriver between the upper and lower casing on the other side, and Voila; it's open.