Do these mount directly to my FJ's factory bumper cutouts?

Yes. These use the factory mounting points on the bumper — no drilling or additional fabrication required. Bolt them in where your OEM lights were.

Will these work with my existing wiring harness?

Installation requires splicing into your factory DRL and turn signal circuits. If you're not comfortable with electrical work, have a shop handle the harness routing. The mounting itself is mechanical only.

Can I return these if they don't fit?

Test-fit the assembly to your bumper before making any electrical connections. Since these bolt to factory points, fitment is straightforward — but verify alignment before committing to the wiring.