How to Remove Google Account from Android Phone ? No factory Reset Required…
Go to Email > Menu > Accounts > Hold finger on Account you want to delete > Remove the Account
You can Change your Google Account is by changing your password from a PC and then restart the phone. You will be prompted for the correct Google Accounts information. You can Change the account info there.
* In Menu, and go to Settings.
* Select Applications > Manage Applications.
* Look for the app “Google Apps”
* Now, select “Clear data” button.
* Now, in the Notifications (top of the screen) you will see a new notification.
* Select “Your account must be updated”.
* Add new Google account information then Reboot your cell phone.