Heres a brief explanation, theres a fair bit to program ...
This assumes you are not using a Voicemail menu for anything else at the moment.
You need a PC with hyperterminal running and a connection setup to your com port with 38400, 8, 1, None. Connect to the front of the SVM with a cable wired 1 - 1, 2 -2, etc using all 9 pins. (1 and 9 are not actually connected if you only have 8 wires !) Pressing CTRL + L should refresh the page, press ESC and login with 0000. Press enter for OPEN BLOCK TABLE and arrow down to MENU. Press enter on the DAY MAIN MENU. Here you will see you can specify upto 6 prompts to be played in succession, most people only use one so press CTRL + Y on the others and change the first one to a new prompt, 2000 is a good one. You can record this later in the Admin mailbox. Press CTRL + D and you will see the AA options. On a new line press enter and press 1, enter to move across to the actions and choose GOTO, enter again and your in the target generator, arrow down to EXTN, pressing enter again will display a list of all your devices, press enter on the group you want 1 to be directed too. Go to the next new line and now enter the details for digit 2, etc.
Now all you have to do is set your ddi in MMC 714 to the voicemail group.
Depending on your knowledge this may / may not be enough detail but it gives us something to start with !
All the Best
Tailor