Removing my name from a car loan

I co-signed a new car loan for my son 2 yrs ago. The car is titled in both our names. Two months after the purchase he was laid off from his work. I made the next 5 payments until he was on his feet again. He has been consistantly late on the remaining payments. He has not made the last two months payments. He has been estanged from us for the last month. I don't bellive he intends to make the payments. He has been employed the past 17 months in a good paying job. I have asked for him to refinance the car to remove my name, but to no vain. Is it possible for me to make the payments and take possession of the car from him or can I have his wages garnished to make the payments?