I did this to a pair of my acid wash jeans that I am constantly deconstructing, ripping, and studding.
I've been doing this in my random free time for about a year now. Taking out the blue thread strand by strand can get kinda tedious. Anyways, I did this to the back pocket.
Grab some studs and a seam ripper/scissors.
Just rip the seam that attaches the left side of the pocket to the jeans down just the left side. Or you can do what this girl did and cut very close to the edge of where the pocket meets the seams and then fray the edges.
Stud the pocket :)