Do I need to replace the rotor and brake pads when I install this?

Not necessarily. The hub assembly is separate from your brake components. Inspect your rotor and pads during installation and replace them if worn, but this assembly doesn't require you to.

What hardware do I need to bolt this on?

You'll need wheel lug nuts and the bolts that attach the hub to your brake caliper bracket and suspension. These are typically factory hardware already on your vehicle—no additional fasteners are required to complete the swap.

Can I reuse my old ABS sensor, or does it come with one?

The assembly mounts where your old hub sat. Your existing ABS sensor can usually transfer over if it's still functional—test it before reinstalling to confirm. The assembly itself doesn't include an ABS sensor.