To upgrade your license, log in to the customer portal by going to https://infusedaddons.com/portal. Your logins were sent to you via email the moment you purchased the plugin. If you forgot the password, click on the forgot password link in the customer portal.
Then next to the license, click on Upgrade License button and select the type of license you want to upgrade to. Follow on-screen instructions and the license will be automatically upgraded after payment.