81 280zx
I am in the middle of redoing my front brakes and wheel bearings, I took my rotor with hub to my local O'reileys, and he said I needed to remove the hub 1st, was a really young kid, so no disrespect, but he may have been wrong.
Anyone know if it can be done with the hubs on ? even though I have removed the 4 bolts holding the hub to the Disc, it seems to be pressed in, extremely tight.

Remove 4 bolts, tap rotor with mallet. Off it comes. May be stubborn with some rust-welds.

The guys at Meineke charged me 10 bucks to press them off and On, total 30 per side to do everything. They were really rust-welded in so I just let them do it.

Mine were same way took a one square pipe and beat it with a sledge they come off

After talking to the tech when I brought my 2nd disc in to be turned, I had removed the races, and he had used them before, his machine/ lathe can grip the inside of the hub, having the races in greatly helps. So he was able to do it with the hub and disc together, but still charged me 30$, but did press in my new races, so it was fair. Seems every shop has a different way of doing it, these guys had a really old machine, but I never saw it.

The brake lathe most oreilly's use can do rotors with the hub on. Some trucks have the rotor and hub as one unit. Its just a mess and it's easier/better to do without the hub.
We use the Accuturn 8944