How to mod stock clutch

Watched a video on YouTube of a guy who has a 07 renegade 800 with 30" silverbacks and it turned them harder than my 1000 with a dalton clutch kit and the same tires. I asked him what he did and he said he cut the ramp on the clutch. His english wasn’t that great so I’m hoping someone could explain what exactly he means and how to do it? The guys name on YouTube is dizefilms