Do these mount to the factory fog light holes, or do I need to cut new openings?

These bolt to the factory mounting points — no cutting required. If your truck came without fogs, you'll have some minor drilling to prep the bumper opening, but the bezels are designed to sit flush with OEM body lines.

Does the wiring tap into the existing truck harness, or is it a standalone circuit?

The harness includes a dedicated switch that mounts in your dash. You'll splice into your truck's battery and ground — standard relay and fuse setup. No modifications to factory wiring needed.

Can I paint the bezels, or are they already finished?

Smoke tint is the final finish. If you want to match a different color, light scuffing with 400-grit and a bumper-grade paint will work — just prep the plastic surface first.