Do these mount at the factory locations?

Yes, these are direct replacements designed to use existing factory mounting points. You'll just need to disconnect the old harness and connect the new one.

Will I need any additional hardware or tools?

Basic hand tools and a socket set handle removal and installation. No drilling or modification required if you're using factory locations.

What if a bulb burns out later?

You can replace individual bulbs without removing the entire assembly — they're accessible from behind once the marker is mounted. Grab replacements from any auto parts store.