Anytime user can change the primary email address with which the user have signed up in the community. There are a few steps with which user can change the Primary email id.
Open the Member profile menu and click on My Settings.
On settings go to the general tab email option. Now hovering on the email option will give the edit option and clicking on it will open options for the user to add another email.
Now click on add another mail id will open a field to write a mail id and add cancel buttons beside. After writing the mail id if user cancel then it will cancel the procedure and if click on add will give the user three option. Confirm email address, Resend verification email & Remove.
Clicking on remove will remove the mail id.
Clicking on resend verification mail will resend to verification email to the mail id provided by the user.
Confirm email address option will open option to put the code user got in the mail in the text box. To confirm the email user have to put the code in the text box and click on verify will add the second mail id to the account.
It will redirect the user to the feed again and user need to go to the settings page again as step 1 and go to the email field. Hover on it will show the edit option at the right most area clicking on that will show two mail id and there will be an option or radio button. Which email id the user will choose through radio button and click on save will be saved as the primary mail id.
This is how user can change the primary email id for the account.