The circuit board is held down by two small Phillips screws.

Using a PH000 screwdriver, I remove them. They are pretty soft and the material wants to give in to the driver, but by pressing down firmly while turning the screwdriver I manage to remove them without damaging the heads too much.

The circuit board's corners are tucked under the case. More prying with my paper cutter gets the top two corners out.

I'm careful around the top because that's where the on/off switch is located, so there might be some cables there that I don't want to damage. I only pry close to the corners and avoid the centre of the top edge.

And I was right - when I manage to open the gap between circuit board and case further, there's the cable.