How do you change @icloud email address

I have been searching but haven't found a solution yet. Does anyone know how to change my @icloud email address? (not my email associated with my apple id, but the actual @icloud email address that I created years ago on my iphone) Sometime it is necessary to change your email address, name change, life events, etc... I do not want to create an alias. There must be a way to dump an email address and create a new primary one.