Do I need to drill or modify the bumper to install these?

These mount at the factory fog light locations using existing mounting points — no drilling or bumper modification required. You're working within what's already there.

What if I need to replace the bulb later?

The amber H8 bulb is user-replaceable from behind the light assembly. Standard H8 bulbs are widely available and inexpensive if you ever need a spare.

Will this work with the factory fog light switch without rewiring the dash?

Yes — the harness plugs directly into the factory switch connector. No dash removal or additional relay wiring needed; it integrates into your existing electrical system as-is.