Change the Google Account Password on an Android Device

When you access your Google account from a PC or other means, and change your Google account password for the account that is also associated with your Android device, it will not be able to sync or connect to your Google account until the password is updated on the Android device.

1. The Easy Way

Wait for the Android device to show a warning that it was unable to connect to your Google account. This will be in the form of an exclamation in the notification area (a triangle with an exclamation mark in it on the notification bar). If you click on that, you should get prompted to enter the account password. If this works, you are good to go.

2. Alternative Method

1. Go to Menu->Settings->Applications->Manage Applications
2. Click on GMail in the list and, if needed, "Force Stop" then "Clear data"
3. Click on Google Apps in the list and, if needed, "Force Stop" it, but DO NOT clear data
4. Click on "Clear Data" on GMail Storage
5. Exit back to the phone's Home and open the GMail app
6. Re-enter your Google account info

If you don't see a notification that Google login has failed after a few minutes, turn the phone off and on to force a login attempt.

3. Another Alternative Method

1. Go to google.com/accounts on the phone browser
2. Sign in
3. "Change Password"
4. Go back to the Home Screen on the phone
5. Open the GMail app, clicked on Menu, then Refresh -- you will get a sync error
6. Wait for a notification to re-enter your password (a triangle with an exclamation point in the phone's notificaiton bar and/or something in the gmail screen)
7. Enter the new password

Some information here is sourced from a discussion on Phandroid. Change Google account password. credit to "astrobill".