It cant be done, at least i have tried to do this and was not able to do it at all. It helps to protect theowner of the account, but sucks for some because their primary email is from a dropped domain.
Its under your Google account setting. You can add or change email address. "You can use alternate email addresses to sign in to your Google Account, recover your password, and more. Alternate email addresses can only be associated with one Google Account at a time"