It is not hard, you must choose the right sequence of drills when you train him. If you start with a low overall player and use the 180 rule, it is quite easy to get skills over 300%.
Hi could u explain this rule please. I can only get 200 stats to but I regularly beat teams with 300 stats, but most of them 300 stats are from upscaled players and 300 stat upscaled players don't seem to be has effective from what I've come up against.