Follow these steps to redeem your gift card:

Step 1When checking out, on the "Review & Pay" page you will see a heading called "Gift Cards & Promotions".
Step 2
Under the heading, click on the button that says "Apply a Gift Card".
Step 3
Enter your gift card number and PIN, then click on the "Apply" button.
Step 4
If your purchase was greater than the gift card amount, then you can select your preferred payment method to pay for the remaining balance.  

If your gift card value was greater than the value of your purchase, you will see a message with the remaining balance on your gift card after this payment has been processed.
Step 5Click on the "Place Order" button to complete your purchase.