What's the best way to get these rotors off? I have never had one apart.

It's held on by the studs, Knock all the studs out and you will have it apart. You probably will need a press to install them with the new rotor.

If it is a dual wheel you will have to remove the adapter between the wheel and the rotor. Non dual there is not one. Then you need to remove the caliper and bracket. Next the axle nut and wheel bearing bolts. Now the sweat starts as the wheel bearing will be most likely stuck in the knuckle. The rotor comes off with the wheel bearing/hub assembly. Then you will need to press the studs out. Rotor is on the back side of the wheel bearing flange. Later models are different. Depending on miles now is the time to think about the ball joints and possibly a new wheel bearing along with the brake job.

It's a dually with the 4850 lb axle.I see 2 different style of rotors one with the 4 openings for the wheel bearing and one that's round.How does the one that's has a round opening come off?

I only see one for 4X4 solid front axle.

Ok.Maybe their stick photo pic is wrong.That makes sense.