i don't think it has anything to do with the phone but how to setup the voice mail via the IVR.
Unfortunately, I have also forgotten how I set it up initially can't give you a 'flow' of what each step is for.
I just called which steps you are not familiar ? These are the essentials:
1. it would ask for language
2. it would ask for passcode
3. then it would read back the passcode and you need to press (1) to confirm
4. then you would need to record your name
5. then you would choose either greet by you or standard greeting
6. then it would play back the greeting with your name
is that what you need ?