Going Live
From the technical point of view you need to make sure to load SubscriptionJS from the Live Instance of billwerk:
<script type="text/javascript" src="https://selfservice.billwerk.com/subscription.js"></script>
Get your publicApiKey from the live settings and update your code accordingly.
paymentService = new SubscriptionJS.Payment({ publicApiKey : "527cc4c951f45b08c493d834" }...
Also update your plan variant ids and component ids. When done with the technical to-dos make sure the PSP settings on the Live System are ready to do real payments. Make at least one real life test for each supported payment method.