Go to Settings > Tap Accounts and backup >
In older operating systems it is called Cloud and Accounts or Accounts.
Tap Manage accounts, then tap your Google Account> Tap Remove Account. Depending on the operating system this option may be under the More options icon on the top right-hand side of the screen
Tap Remove Account to confirm >Tap Add Account
Tap Google>Enter your Google Account details
Follow the onscreen instructions to finish adding your Google Account