Will these lights require cutting into the bumper or drilling holes?

These are designed as a direct bolt-in kit for factory fog light locations. If your Yaris came with fog light provisions, installation uses those existing mounting points. If it didn't, you'll need to confirm mounting compatibility before committing to install.

Are the H11 bulbs included, or do I need to buy them separately?

Bulbs are not included in this kit. You'll need to source H11 bulbs separately — they're standard, inexpensive, and available at any parts store or online retailer.

Does the switch come wired and ready to plug in, or does it need soldering?

The harness and switch are assembled and ready to connect. Exact connector type and wiring preparation aren't specified — test-fit the connectors before final installation to confirm they match your vehicle's electrical setup.