Doing the short shift mod on a mk3 gearbox is almost the same as the 225 one, its the R26 one that the problem, as that has to be milled out.
Mark a point 25mm from the original ball stud drill a hole I tapped mine and put a nut underneath to lock it off, not sure you need it , belt and braces tho, i think on the 250/265 you have to move or cut a bolt that is in the way. Not done mine yet, sort of happy with it, will be a winter job