Will these fit my bumper without modification?

These mount at the factory side marker locations with no cutting or drilling required. You're just swapping the old units for the new LED versions.

Do I need to wire these to my existing harness?

Installation method not specified in the product data — test-fit the connection before committing to your wiring setup. OEM harness compatibility can vary; have a basic multimeter handy during install.

Are these sold as a pair, or do I need to order left and right separately?

You're getting both the driver and passenger side markers in one order — no separate purchases needed.