Will I need to buy separate fasteners to install this?

Yes. The assembly itself is complete, but you'll need to source the bolts and hardware that connect the knuckle to your control arms and strut. Check your factory service manual for the correct bolt sizes and torque specs.

Can I reuse the old rotor and caliper bracket?

The rotor and caliper bracket stay on your old knuckle — they don't transfer to this assembly. You'll need to remove them from the original unit and install them onto this loaded knuckle before bolting everything back together.

Do I need any special tools to install this?

Basic hand tools and a torque wrench are all you need. Since the hub and bearing are already pressed and torqued, you're just bolting a complete unit into place — no bearing presses, no alignment equipment required.