bleepingcomputer[.]com/news/technology/google-now-lets-you-change-your-gmailcom-address-rolling-out/
It's not *exactly* changing you email address, but adding an alias, so you'll have 2 email addresses for the same account. Borrowing a page from Microsoft, the new feature is slowly rolling out, so you may or may not see it yet.
If you don't see the option under Personal Info > Email > Google Account email, it means the feature is not yet available for your account.