So I had a go this evening at taking it apart. They really don't want you fixing these things.
Managed to get the covers off the side, they lift up a little then rotate and ping off. On one side you can see a screw for a pot to adjust it.
I manged to lever the case enough to get one side over the peg but the other side wouldn't go and I didn't want to break it. Might give it another go in a moment.