There are a couple ways to change a product and/or flavor:
1. You could cancel the current subscription and create a new subscription order (shop as normal on the website and add to cart a Subscribe & Save product) and check out using the same email address. Or, while logged into your account you could also click on "Add a Product" located on the bottom of the page to initiate a new subscription order.
2. Instead of cancelling the subscription and creating a new subscription. You can log into your account. While in your subscription account, click "Swap" next to the subscription you want to change and search for the new product or flavor. 
