A password change is effective immediately. The wallet is saved to the current directory with the new encrypted password.
Note: If you are using a wallet with Auto Login enabled, then you must regenerate the Auto Login wallet after changing the password. See Enabling Auto Login
Select Wallet > Change Password.... The Change Wallet Password dialog box appears.
Enter the existing wallet password.
Enter the new password in the New Wallet Password field.
Re-enter the new password.
Choose OK. A message at the bottom of the window confirms that the password was successfully changed.