Will these plug into my existing wiring, or do I need an adapter?

They're designed for direct connection to factory connectors. Confirm your connector type matches before ordering—older Toyotas sometimes have minor variations, but most bolt straight in.

Do I need to remove the old bumper to install these?

Not necessarily. You can usually access the mounting bolts from underneath or from inside the bumper cavity with the wheel well liner pulled back. A jack and some patience beats dropping the whole bumper.

Are these sealed against water intrusion?

They're new stock units with hard panel construction. Inspect the lens seal and connectors before installation—if gaps exist, a bead of clear silicone around the mounting base prevents moisture trap.