Michael's father is giving him an interest-free loan for a $20,000 car. Michael plans to give his father a $5000 down payment and pay $500 per month. The total amount paid can be represented by the linear function T = 500m + 5000 where T is the total paid to his father and m is the number of months. If Michael gives his father a $10,000 down payment instead, what part of the linear function should Michael change?