The first step is to take him off the insurance , 2 reasons for this, one it means you will not get a claims history for an accident he has and two, he can no longer drive the car. As I just said, if you are the registered keeper he needs your permission to get insurance on it or drive it on another policy. Then report him for driving without insurance , the police will seize the car and you can reclaim it by producing your documents and insurance.