Fitting brake disc backing plates

How do you fit the brake disc backing plates as the hole is smaller than the brown disc part in the picture so assuming I have to take the hub to bits. How does the hub split apart or whats the easiest way to do this???

Thanks Luke

Think you,ll need a press mate,  to press them out

if it was me i would cut the front of it so it can slip over. mk2 ones are half moon or even smaller than that and they dont explode

Good post, just found it, I'm about to do this and didn't fancy splitting the hub!
Will add some pics when it's done to see if it works!!