i just took some scissors and cut them straight across.
then i just took a random brush...i think it was a cheap suede brush you get out of a kiwi shoe care kit.
but the bristles were really rough and just brushed the hem downward until it looked distressed to my liking.
i did have to add a horizontal reinforcement stitch to the inseam of my jeans because after i cut them i could tell they were going to unravel.
honestly, it was super easy. i didn't even know what i was doing. i know nothing about sewing either.
but they've held up great after a lot of wear