I've bough a "flip" key on Ebay for my 2008 Focus mark 2.5 and I need to remove the "guts" from my current remote key and put them inside the case of the new flip key.

I've taken the old key apart to the point where the lid has come off which contains the battery but the electronics are fairly well anchored into the other half of the key and I don't want to use too much force to remove them in case I damage them.

Has anyone done this and got any tips how best to remove the electronics?

From what I remember they're just anchored at the corners, with a tiny plastic mounting peg that slots through a hole on the PCB - there is nothing else holding it to the bottom part of the fob. You should be able to prise the PCB off with very little effort, using a flat screwdriver. Note that when you remove it, it'll be very unlikely that you'll be able to put it back it the old key as it won't sit right on the damaged pegs.

As far as I'm aware there is no other way of removing it.