Toyota Airport Motors giving this facility to install front view camera.
I did below steps:
1. Cut the wire from back view camera to infotainment.
2. I used 14 point OMRON relay. It was 12Volt
3. With direct point of relay i connected that cut wire.
4. With the change over points i connected front camera wire.
5. I used corolla fog lights wiring for button.
6. When we switch ON the button the relay activates and change over the camera from back to front.
It is very simple but need technical mind. For the person who has electoral circuit knowledge i give them a tip that its wiring is same as SARA change over switch.