How do I change my icloud email

You can't change/remove @iCloud.com, @me.com or @mac.com addresses unless it is an alias you created after the Apple ID was set up.

iCloud: About your @icloud.com, @me.com, and @mac.com email addresses.   *

iCloud - Create or change email aliases.   -

Changing your iCloud mail means that you create a new mail account and therefore probably also a new Apple ID.

I assume your Apple ID is linked to your iCloud email address.