Hello, first of all, I'm not sure of the condition of your thighs. I will just give you some general guide lines. You definitely want to do cardio regularly. Cycling, elliptical, swimming, etc., are a few cardio methods to consider. You need to find something that you will do regularly. Preferably in the morning on an empty stomach will enable you to burn more fat when doing cardio. The exercises that you can perform for your thighs are lunges, leg press, Leg extensions, leg curls, and squats. Are your thighs the only place that you are holding fat? Are you on a regular workout program now? For how long have you been on a regularly program? Are you getting results every where else other than your thighs?
Your genetics plays a good part in your body makeup but you can improve on it if you work hard.