From the Visual Voicemail inbox, tap a message to open it.
Tap 'Create new contact' or 'Add to a contact'.
Enter or edit any of the information (e.g. name, phone, address, email, etc.) then tap SAVE (upper-right).
If creating a new contact, refer to Add a Contact for assistance.
If adding to a contact, select a contact then add/edit info as preferred then tap SAVE (upper-right). Refer to Edit a Contact for assistance.