From the settings menu tap Accounts and backup. Tap accounts and select your email account. Tap Remove account. Press the button confirm to remove the account.
How do I remove an email account from my Samsung phone?
You can find the settings of your email account by swiping down your phone from the top right until you see the 3 horizontal lines. After that, tap Settings. Then tap Accounts. The account you want to delete should be the first one.