Adding/Changing Name to NEC multi-line phone (by 2 users)

I am unable to change the name that is displayed on the screen of our office phones. they are NEC electra elite phones. (that is what the guide calls them) I have the character entry codes, but no where in the booklets does it say anything about what to press to change the name displayed on the screen. (the question about changing the time and date of the last phone had the answer that my book had so it was the same phone I assume.) Thank you so much for any help you can give me!