How to install Avast to a newly built computer?

I have purchased protection for a number of computers and have an unused license. I am in the process of scraping my old computer and rebuilding a new one. Seeing no assistance anywhere I went to download Avast with the intention of covering my new build with my unused license valid until November 2016. However, before I can download the trial Avast file, you demand my credit card info. This worries me, I’m betting I’m going to get billed again.

How do I get the Premier Avast Program for which I have purchased a license without being billed?

Here you go: https://forum.avast.com/index.php?topic=179855.0