How to replace hand brake cable on a 1998 106 gti with disc brakes?

Hi im just wondering how exactly i replace the handbrake cable on this car as i would like to know as much as possible before attempting it, i know you have to take the heat shield off above the exhaust to get access to the underside of the handbrake, what my main concern is how exactly does the old cable come out of the caliper/hub and how does the new one go in?

Thanks, Sean