1. Open the Settings menu and then the Android
2. Tapped Out here on "Accounts"
3. Typing the "Google Account" and then click your e-mail address
4. Now choose the top right "more" and the pop-up window "Remove account"
5. You now have the Google account successfully removed from your Samsung Galaxy S6.
6. Now you have your smartphone with your new Google Account link
7. Opens again Menu -> Settings -> Accounts. Tap on the plus symbol
Then 8. Selects Google as account type and follow the setup wizard.
You have now successfully completed the Google account on your Samsung Galaxy S6 changed under Android.