Assistotalk

For Android

1. Tap Settings> Accounts> Google, select the account you want to remove.

2. Tap menu icon> “Remove account” icon, then a message will prompt to ask for your confirmation. If you are OK with that, tap “Remove account” to continue.

After that, the Google account will be removed. If you run into some issues during the process, you may find a solution from below link.

http://www.assistotalk.com/how-to-delete-gmail-or-google-account-permanently/