Unfortunately there is no current public method for this. There are some releasers and release groups with access to a tool called "WVDownloader", but it's being kept really secret. I don't have it either. One of the reasons it's being kept so secret is probably to to prevent Amazon from working around it as quickly as last time, but I'm sure they're aware of the exploit, as it's existed for 3-4 months now. Some people claim to sell it, but if you can even get them to reply to you, there's always the risk of a scam - and even if you're not scammed, there's another version that simply captures the Widevine output like a capture card and saves it to a ~300 GB raw file that you have to encode afterwards. That's better than nothing if you don't have a capture card and a HDMI splitter that can break HDCP, but obviously it's not a lossless download which is preferred. But if you tell me things you want in particular, I can take a look if it's been already ripped, since I'm on a few private trackers.
@Djodjara There's no such software floating in public. I advice you to FORCED them (those people who has WVDownloader) to do shows for you on your Amazon account, if you can because this is the only way to get Amazon Rips. I know my advice seems really wrong but if you Amazon Rips, that's how you can get it.