The first thing to do is take out the one visible case screw, near the on/off switch in the top left corner of the phone. I used a small cross head screwdriver.
I took a macro shot of the screw, to give an idea of the screwdriver size needed. It's pretty small.
The next screw is hidden behind a sticker in the top right corner of the phone. It's the same size as the exposed one, so ignore the sticker and just unscrew it!
Presumably the sticker acts as a tamper indicator in case of returns, though I don't remember this phone coming with a warranty.
I didn't know it at the time, but these two top screws are all you need to remove to open up the case. I thought there might be a couple more hidden under the long sticker at the bottom of the phone.
... Instead, there's another sticker, showing the version number and serial number. I think mine is an earlier KA08, I've seen ones on eBay with Java capabilities.
So the screen cover can be prised off at this stage. Like a lot of modern kit, there are flimsy plastic catches holding it to the main body of the phone. The next few photos highlight the position of the plastic catches, 3 on either side of the phone. Prise at these areas to avoid breaking them or straining the thin cover unnecessarily. The cover is surprisingly pliant rather than brittle and is less trouble to remove than it looks.
The photo above shows the phone in profile, the top of the phone toward the left of the picture, and the bottom to the right. Start by prising the top left corner, where the highlighted markers are drawn, then the middle section, then the bottom. The bottom is the stiffest plastic catch. I took a couple more shots to show the catches more clearly:
* In the picture below, you can see the area to prise the top and middle catches roughly corresponds with the sim card slot area...
* The catch towards the bottom of the screen is more awkward than the others. I used a craft knife to prise it open. You can see (or squint, sorry about the blur) there is a lot of dust inside the phone.