The hole centres for the reverse camera mount sit 28mm apart.

Take your factory landcruiser reverse camera mount and measure the centre of the mount.

Measure 14mm each side of the centre point.

Drill the 2 point you marked from the centre point. Ensure you place something over the camera while drilling to protect it. 

Place anti seize on x2 M5x20 button heads and fasten the mount to the bumper like so. 

Fasten on nylocs.

Securely cable tie the reverse camera loom away from any hot or moving parts.