I was reading on here a while ago about this, and someone said that the diesels didnt have removable caliper carriers so the whole hub had to be removed and swapped with one that did and then you could do it, if this is wrong then no not to difficult, remove old callipers and carriers put new carriers and callipers on, replace discs with cupra r ones, bleed brakes and away you go ( put 18" alloys on first)