Ricoh Aficio 5000L Fax Printer-Adding names to Group name

I work for a company that has a Ricoh Aficio 5000L Fax Printer. We currently have a customer database that we can e-mail fax information to our clients. We need to make changes in our Groups from time to time, since our customers do have personnel changes. I have read the manual and cannot find the exact item that covers this problem. I can edit the group and delete all the names in that particular group, which I do not want to do. I would like to add names to a group. Since the person who was trained for our company on this machine is no longer here, we need someone that is able to do this, and I was asked to do it. Again, I need to add names (e-mails) to an established group, and need to know step-by-step how to accomplish this task. Thank You