It is important that your team has someone as an Administrator. This person can manage account users information, such as passwords and login ID’s, and add and remove accounts from the portal. It is important to ensure your administrator is a long time user with the company to maintain better security of their user's Portal Access.
Please see the following articles for more information:
Edit User Access
Edit User Information
How to Change a Password
How to Limit Access to Users
How to Remove Portal Access
How to Create a New User
How to Deactivate and Reactivate Users