In the User section you will be able to see all the names and their corresponding extensions. If an extension has a different user and you want to update the name, you can click on the name to edit.
The User profile window will appear, where you can type the new name. Make sure you click on Save when you are done.
The user profile window has a few other options as well. You can select if you want their name to be announced in the company’s directory (to be used when you have an Auto Attendant). Having a check mark on Announce in Audio Directory means their recorded name will be played. Having a check mark on List in Directory means that it will be an extension available to search for, when asked for the 3 digits of the persons first or last name.
One other thing you can do here is add their email address. This is to be used if they ever want to enable the voicemail to email option ON (this is done in another section).