I sold a car to a guy and he said he would have the rest of the money in a month and didn't can i repo the car?

So I sold him the car he made payments for about a year then he told me if we did a title change he would have all my money next month we got a title change with me as a lean holder after the title was under his name the month date come and he only has the payment amount not the total now he is saying he just wants to continue the payments which will take about another few month can i legally get this car repossessed