I've done the change on a couple of Fuji Ace bikes with front QR and rear bolt-on.

In both cases I kept the hubs, and just replaced the axle. It was a bit of a pain. As mentioned above, it used different threads, thus different axle, cones and lock nuts. Also at least one had the dust seals attached to the cones, so those got replaced too.

On the rear, it is easy to get the dishing off just a bit, so that must be fixed too.