[scooberblue]

quite easy actully..
remove whell and unbolt brake caliper and pull of the disk!

my old green classic had a metal on metal noise an turned out to be knackerd disks.
thay looked fine but inside the disks are handbrake shoes that use the inside of the disk as a drum and it was the inside part that was worn out.
definatly worth removeing disks just to inspect if nothing else.