Log into your account settings by clicking the gear icon in the upper right-hand corner of the screen. Under your personal information tab, you will see a section for contact information, where your primary email address is listed. Click on edit next to your email address to be taken to a screen which gives you the options to include an additional email or
How to Change Primary Email Address in Facebook Account
How to Change Your Primary Email Address on Facebook!
To remove your email address from Facebook, tap the top right of Facebook. Scroll down to Settings and tap Personal Information. Tap Contact Info in Account Setting, then your desired email address on the next screen, and press Remove.
Sounds like some of you have trouble updating your primary email address. First, go to account settings in General. If the e-mail address you want isn’t currently listed there, click “Add another email” and then choose it as your primary email before you can change it to that one.
Go to Settings at the top right corner of your screen. Choose Settings & Privacy from the drop-down menu. Go to Contact in General Account Settings and fill in the new email address you’ll be using instead of the existing one.
Tap the top right to go to your profile. Scroll down and select Settings from the drop-down menu. In the Account Settings area, scroll down until you reach Personal Information, then Contact Info. After that, tap Remove next to the email address you wish to delete.
Go to the Google homepage and log in to your account. Select “Account” from the drop-down menu next to the profile picture, then “Edit” next to “Email Addresses.” If necessary, click “Remove” next to the alternate email address you intend to use as your new primary username.