change iCloud email and account

From some months I'm receiving a lot of spam to my iCloud email and for security reasons I want to change it to another @iCloud address.

I've created a new gmail account, changed my iCloud account to point at the gmail email and changed the iCloud account of all my devices to the new gmail iCloud account (so from @icloud.com to @gmail.com); now I want to create a new @icloud.com email but I don't know how to do it, also if I try to access to www.icloud.com with my old @icloud email it works.

How can I do it? I suppose it's possible because the Apple support pages tells that if your iCloud account is connected to a @iCloud email you can change only to another iCloud email (but doesn't tell how to do it without create an all new account loosing everything)

thanks to everyone who will help