I was in the process of upgrading my wheel studs and thought I'd take a few pics and provide the info for anyone else that may want the extra piece of mind of having larger wheel studs. Parts list at the bottom.
First off, my 2015 800 EX came stock with 10mm wheel studs. While they may be fine for easy riding, they are pretty much the same size that is on most ATV's and I felt that I would rather have the extra strength of something better. Especially since we ride some pretty rough stuff sometimes. Secondly, I was adding wheel spacers and wanted/needed studs that were a bit longer so I could use all of the threads in the spacer mounting nuts, again for more strength.
Disclaimer: Obviously this is not a complete How-To: please use caution when working on your machine and make repairs at your own risk / and within your abilities.
Once you machine is jacked up and the wheel is off, you must remove the cotter pin that holds the axle nut on. I cut mine with a grinding disc and tapped them out with a hammer and small punch. You should use new ones anyhow. once the cotter pin is out, remove the axle nut (36mm socket) or large wrench.


Next you will need to remove the two bolts that hold the caliper on. The rears are an 8mm hex head. The front hubs have two 13mm bolts. As you can see one of mine, and likely yours, is full of mud. Clean the heads out with a pick or air before trying to remove them. You do not want to strip the heads out due to pour penetration of your hex tool!


Tip: on the rear hubs, you need to remove the lower spindle mounting bolt (15mm head and nut) so you can pull the spindle away from the machine some to get the lower caliper mounting bolt out. This extra step will save you some grief.

Once the spindle mounting bolt was out, I stuck a pry bar handle between the spindle and the control arm so I could free up my hands to remove the caliper bolts. I just laid my caliper on top of the upper control arm, however it is best to tie it up so it don't fall down and damage your brake line.

With the caliper out of the way you can now pull the hub off with the brake disc.

Once it is off, you will need to remove the 4 hex heads (6mm) that hold the brake disc on the hub. Same with the caliper bolts, clean the heads out first.

With the brake disc out of the way, you can now remove the old studs from the hub. This can be done several ways, either using a large C clamp and sockets, using a “front end service kit” for vehicles, a press or you can place the hub an a solid surface and tap them out with a hammer. I used a brass hammer so I can save the studs for use on other projects (we have several ATV’s). BE CAREFUL not to hit and/or damage the “ears” on the hub if you use a hammer!


Once the studs are removed, you will need to drill out the stud mounting holes slightly. The new studs have a slightly larger knurled area and needs some clearance to go in. The studs I chose have a knurled area that measured around 12.2mm. I drilled the holes out with a 15/32 drill bit that measured 11.8mm and this worked perfect.
I used a drill press and went slow. This can be done with a hand drill if you are very careful to keep your drill straight. I also suggest using a good bit and some “cutting oil” while drilling.

Once all four holes are drilled out, the new studs can be installed. I used a press to put mine in, but this could also be done by the methods mentioned earlier (C-clamp and sockets, front end service kit which can be “rented” for free at most chain auto parts stores).


Once all four are installed, clean the hub good to insure there are no metal shavings in the axle spline area before beginning reassembly.
Reassembly is the reverse of the disassembly procedure. As you can see, the new studs are beefier than the stock ones.


DON’T FORGET TO INSTALL A NEW COTTER PIN!
The studs I used to replace mine were M12x1.5 that fit Honda vehicles from 1980 - 2020 and are rated 10.9 so they are a significant improvement. The manufacturer is Dorman and there are several part numbers depending on whether you want one, 10, or 40 of them. Another advantage to this if you were ever to damage or break one, you could walk into an auto parts store and buy a stud for a "Honda Accord" and be back on the trails sooner.
1 - 610-269.1
10 - 610.269
40 - 610-269.40
The lug nuts I used were from amazon and are just standard m12x1.5 acorn lug nuts. i think 20 of them were under $20.
https://www.amazon.com/dp/B00B2FCAGY?psc=1&ref=ppx_yo2ov_dt_b_product_details