I found this at My Services FAQ, but the print was really small and hard to read, so I am reproducing it here: (Used MS Word to format it nicely). Hope it helps! Please note: Voicemail service may be included with some TWC packages. As an optional add-on service, it is generally $3.95 a month.
Setting Up TWC Digital Phone Voicemail
(Does Not Apply if you already have an answering machine)
It will take a few minutes to set up your Voicemail account. Once setup is complete, your Voicemail will be ready to receive messages.
1. Lift the handset of your Digital Home Phone.
2. Dial your home phone number, wait for your Voicemail to answer and press the * (star) key, then the '5' key.
3. The Voicemail system will ask you to press the '#' (pound) key.
4. The Voicemail system will ask for your temporary Personal Identification Number (PIN) — which is the last 4 digits of your telephone number.
5. The Voicemail system will prompt you to select a permanent 4-digit PIN and to press the '#' key. Select a PIN that is easy to remember, but difficult for someone else to guess. For example, do not use your phone number, house number or birth date.
6. The Voicemail system will ask you to verify your PIN by entering it a second time and pressing the '#' key.
7. The Voicemail system will prompt you to state your name and press the '#' key. If Voicemail will be used to answer calls for multiple people, you should record a name that represents all individuals in the home. For example, 'Sam and Rebecca' or 'The Smith Family.' When completed you may:
8. The Voicemail system will ask you to record a greeting followed by the '#' key.
This is the greeting callers will hear when you are unable to answer the phone. It is good practice to write down the greeting in advance of recording it to ensure all the information you want is included.
9. Once your Voicemail account set-up is complete, you will have the opportunity to listen to the main menu, or, if you are finished, simply hang-up to exit. You may also exit by pressing '#', then '9'.