(reposted from HBO Leaving Amazon thread)
Q: Now that HBOMax is gone from Prime Channels, how do you transfer your subscription from Amazon to HBOMax direct without having to change your login, password, etc?
A: From the HBOMax web page use the menu to sign-out from your account (if you have not already done so). Then refresh the page so that it offers you the opportunity to subscribe to HBOMax and begin the subscription process. When you reach the point that it is asking for your email, name etc., ignore those fields and using the sign-in option at the top of the screen with your existing login and password (the one that you created based on your Amazon subscription so that you could use AnyStream with HBOMax).
This will put you on a path to 'change' your subscription to whatever you choose, under your existing account. No need to change login in AnyStream or anywhere else. You must provide a new payment method, of course.