The route I took was slightly different. Created a situation where I had updated my main Google account, invoked 2-step verification which creates a situation where you cannot log back in and you cannot remove or update that account via the Play Store or the Google Settings. In fact, you're almost stuck from what I saw.

My steps (which may not be helpful) are as follows:

• Stop Android services
• /opt/alien/data/system/sync resides the account.xml.

• Uninstall Google Play Store via UI (Phonesky.apk will stay in /opt/alien/system/priv-app this way)
• Reinstall Google Play Store via terminal

• Reboot or Restart Android Services

The Play Store will start sending out notifications for already installed apps, update itself and then you can sign-in with your new credentials and input the 2-step verification credentials. Via the Google Settings, I could add a new account, but not affect an existing one. Gmscore.apk seems to facilitate connection to the Google Play Store, but if you have to edit your password - it will refer you to the website and not allow you to re-enter your credentials. That was my experience unfortunately which led to the above.

On an Android device, you'd just enter into the Settings App (com.android.settings.apk), then update your login credentials. On this part, I could be wrong and an icon is not being created (which is not too far out of the scope of this thread).