Car Loan outstanding?

My mom died recently and she had a car the loan is still outstanding. I have been paying the loan with no problems, but they don't know she has ped. I would like the car to be in my name, do i have to make myself Executive of state or my dad. Or would i have to make a a fake doc. put her signature on it and act like her signed the car over to me and of course get it notarized.