How to Refinance Your Car Loan.1. Collect documents. Find a recent payment stub from your current auto loan and make sure you know the following:2. Evaluate your credit. If you’ve made all your car loan payments on time for a year or more, your credit has probably improved and there’s a good ...3. Apply. Apply to several car loan refinance companies so you can compare interest rates and find the best offer. Note that some lenders will have ...4. Run the numbers. Using an auto loan refinance calculator, first enter information about your current loan. Input the original loan amount, your ...