All of our consumer loans accrue interest on a daily basis (you may have seen this referred to as "simple interest" in financial magazines). Whenever any payment is made, the interest that’s accrued up to that day is always paid off first, and everything else is applied to your loan’s principal.
This “simple interest” method is a benefit to you because the faster you pay off the interest that has already accrued, the less interest will be due for the next payment, and therefore more of that payment is applied to principal. And, as the principal is reduced, so drops the interest that accrues each month.
The best strategy to payoff off your loan early is to make principal-only payments once a month on the same day that your regular payment is processed. Since your regular payment satisfied the interest that’s due, all additional payments would go directly to the principal. It's always to your advantage to knock down the principal as fast as you can early in your loan. It reduces the total interest you pay, making your loan pay off sooner.