1. Log into your account. If you don't ave an account, see below.
2. Add the "buy one"product (or BOGO box) to your order.
3. Don't add the "get one" item. It'll appear in the cart at checkout.
4. Click "proceed to checkout" to review your order.
5. Select "process now"
6. The order must process during the promotion time. Don't save the BOGO to process later.