Changing your Google password
If you would like to change your Google password, e.g. to prevent someone who had it from accessing your account or to find out which programs access your Google account, you may have to change it in a few places:Google's security page: https://www.google.com/settings/security. Just click on the edit button behind the password field to change your password.
If you have used other ways (e.g. access tokens) to give programs or websites access to your account, please click on "Manage apps" to review and maybe remove them:
Additionally you might have created "application specific passwords". You can review and remove them under https://myaccount.google.com/security