You can get a stud with a bigger knurl but retain the stud size (consult a Dormann catalog), the stud is likely 14 x 1.50. If you go that route I'd ream the hole to the new knurl size (there will be an exact specification for hole size depending on what material it is being pressed into, smaller for aluminum and bigger for steel) drilling it can be tricky and it may end up off center or crooked, you want the stud to be perpendicular to the flange face and not at an angle. It's best to remove the wheel flange and perform repairs with a mill or drill press, and then use a press to reinstall the new stud. You may get lucky and find a replacement stud with larger knurl and not have to enlarge the existing hole. An adjustable reamer is the best way to enlarge the hole IMO if you need to though, and press in the new stud DO NOT use a lug nut to pull it in. If you don't have access to a press you must use a thrust bearing and washer under a nut lubed with anti-seize to pull in the stud. The flange is aluminum and very easy to fawk it up.
