Will this plug directly into my factory wiring harness?

Yes. This assembly uses OEM-style connectors and mounts at factory points — no rewiring or adapter harnesses needed. Disconnect the old unit and plug in the new one.

Do I need to remove the bumper to install this?

No. Access is straightforward from the engine bay. You may need to remove a trim panel or fastener depending on your vehicle's specific configuration — test fit before committing to any disassembly.

Does the bulb come installed, or do I need to buy one separately?

The assembly ships as a complete unit. Verify bulb condition upon arrival and replace if needed — bulbs are standard replacements available at any automotive retailer.