What is the topic sentence of this process paragraph?

Sentence $1$: Many people pay high interest rates on car loans simply because they are unaware of the easy steps to refinance.

Sentence $6$: Next, call your lender for the payoff amount and find out how long until the quote expires $($usually five to ten days$).$

Sentence $9$: The fifth and final step is to make sure the original car lender has issued a notice stating that the loan was satisfied in full.