how do I sell my car with a lien still on it
First check the pay off amount and the value of your car. If you are upside down come up with the money to pay off the difference. I would recommend doing the transaction at your lenders office if possible.
Your buyer can send a check to the bank for the balance and a separate check to you for an overage. Let the buyer insure the car (& you keep insurance) but let buyer keep your plate til they get title.
You need to make sure the loan is paid off. Don't trust the buyer to do it for you because if they stiff you, you are still liable for the loan payoff!