Change password If you would like to change your password, e.g. for security reasons, you have to change it in your Google account, in the Android "Settings" app and, depending on how you sync, also in CalenGoo:
Google account To change the password of your Google account just open http://accounts.google.com in your Browser and sign in. Then click on "Security" and "Change password".
Android Settings app In the "Settings" app you can find a section "Accounts". There you should find your Google account and a method to sync it. When it determines that your password is wrong during the sync, it will ask you for a new password.
CalenGoo Just open "Settings", "Accounts" and "Settings", "Tasks" in CalenGoo. If you can find your Google account there, just tap it and choose "Change password" to enter your new password.