I want to lose weight fast. I'm 5 foot 9. I weight 185 and I want to drop down to 160. What is the fastest to do so safety?

Diet Exercise. There is the starvation diet where you need 2000 calories lower your intake to 500 calories, drink plenty of water, walk or exercise more than usual to burn body fat already stored in the body, more fruits and veggies. You are not that overweight, you can reduce x few months. Good luck!
See a doctor. You need to see a professional for advise about weight loss.