They are pretty soft metal, so easily done! The thread pitch for the retaining ring on the
front wheel is 1.5mm, the same as an M10 bolt. Luckily that is the same as the oil drain plug. I just changed mine so I had the old one kicking around. Run that bolt with plenty of pressure around the retaining ring, and also on the hub inner threads. Any spots that are especially warped, like on mine where I used a punch to turn it out, and where the original stakes were drilled out, use a small jeweler's file to get rid of the big chunks, then the M10 to reshape.
Rear wheel:
Sprocket carrier: 1.00mm pitch, same as an M6.
Hub: 1.5mm pitch, M10, same as front wheel.
