Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
I don't quite understand the question - could you phrase it differently?
To 'change message being saved/forwarded' suggests vaguely that you want to change the *location* they are saved to - perhaps the destination mailbox for the 'general messages left' or 'messages left generally'. Or perhaps the messages left at a given incoming phone number, are being saved in one mailbox or message box, and you want them to be changed to be saved in a different mailbox or message box?
The phrase '...to an individual's message code' is not very specifically significant. Does that mean 'the login code or password ***** an individual' ? or does it mean, 'the mailbox i.d. code for an individual' ?
However the task you are asking about turns out to be, you will certainly need administrative access to the phone system or the voicemail system box. Do you have that access already?
If so, you would log in first, proceed to the appropriate section of the settings, and change the setting appropriately, then log out properly to close the session (for safety and stability of your phone system or voicemail system's administration) and proceed to test whether the result was what you wished.
So let me know, please. Thanks.