From the User's Phone:
From the user's phone, dial into the extension of the voice portal (or dial *62).
Press the star key *
Enter the voice portal extension
Enter the voice portal admin password and the pound key #
Press 1 to change the AA greeting.
Enter the AA extension and the pound key #
Press 1 to change the Business hours greeting or 2 for the After hours greeting.
Follow the voice prompts to record your greeting.