Will this mount using the factory holes, or do I need to drill?

This assembly mounts at factory rocker points with zero drilling. It bolts directly into the existing mounting locations on your vehicle.

Does this come with the bulb and wiring harness?

The assembly ships as a housing only. You'll reuse your existing bulb and harness from the OEM unit—swap the electrical connector and you're done.

What's the return process if it doesn't fit right?

Test-fit the assembly before final installation. If there's a fitment issue, contact support with photos and they'll arrange a replacement or return. Most bolts come hand-tight so you can verify alignment before torquing down.