Click on the link "American Express Membership Rewards" under "References" at the bottom of this page. This link will take you to the search page where you can look for flights.
Log in to your American Express Membership Rewards account by entering your User ID and Password in the box titled "Log In." This will allow you to see how many points you have accumulated.
Search for your flight by entering your flight criteria, including departure and arrival location and dates. Click "Search Flights" to continue.
Choose the flight you want from the results page. You will see a box next to each flight with the cost of the flight in American Express Points, US dollars and the total number of American Express points you have. You need at least 5,000 points to redeem for a flight. Click the prompt at the bottom of the screen to continue to the billing page.
Select how you want to pay for the flight. You can select to pay for the flight using only points, using some points or using no points and paying only in cash.
Enter your credit card number and billing information. Your card will be charged the full cost of the flight, but if you used points, you will see a credit on your billing statement in the amount of the flight or the portion of the flight paid for by points.