Go to your computer, open the Settings app, tap Accounts and then select Sync. Select where WhatsApp should be stored: On Your Phone or Computer. If you’re using AirDroid 2 or 3 on Android or Mac, you’ll need to move it to a PC in order for this guide to work properly. To remove it from Ifrize

Open your Google Account on Google.com and sign in. select “Account” from the grid icon in the upper right-hand corner. click “Delete your account or services” under the “Account preferences” heading. Select “Delete products.”

Tap on the Mail icon and then Settings. If necessary, select a new password for your account. To completely delete an account, scroll to the bottom of the Mail page and select Delete Account. Re-create your account by going back to the primary Mail settings pane and tapping Add Account.

To delete an account, go to the ‘ACCOUNTS’ section and select the relevant email account. (at the bottom; may require scrolling) Tap To remove this account from your iPhone, touch Delete Account. Confirm by tapping Remove. Delete Account

You can’t just change your Gmail name without creating a new email address. You won’t be able to modify your username or actual email address. You’ll only be able to alter the account’s name. If people have you listed as something else in their contacts, that’s the name they’ll see.