Chewed wires : Brake actuator

Hey, I just bought this Prius V with 65k miles, and noticed a weird noise when I push the brake hard to stop. I looked under the hood and found a massive rodent nest tucked under the cowl tray. When I checked the wiring harness right behind the brake fluid reservoir I found that a mouse or rat completely chewed through a black wire right at the main connector plug, leaving the copper totally frayed.

This looks like it's directly causing the braking issues.

Please how can I repair this wires, and what oem parts should I buy .. thank you