When I first switched to 5/8" studs, I asked around about drilling and tapping my axles myself. EVERYONE said send them back to the manufacturer to have it done. So back to Moser they went. Biggest problem was finding a box to ship them in. I've kept a couple of axle boxes in storage since then, lol. Kind of like header boxes. Don't think about it until you need one, then it's a PITA.

5/8" studs makes changing tires/wheels so much easier too.