Products cannot be switched directly on the account page. To switch, you'll need to start a new subscription for the preferred product and cancel your existing one.
Step 1: Start a new subscription
Log in to your account and place a new subscription order for the preferred product. Note: this order will process and charge immediately.
Step 2: Cancel the existing subscription
Go to the Subscription(s) tab.
Scroll down and select Edit Subscription.
Click Unsubscribe for each item to cancel.
Once unsubscribed, those items will no longer ship and only the new subscription will remain active.