Account Admins can see and manage users in an organization by visiting Settings>Account Settings>Admin Console>Members (linked here).

From here you can easily add a new team member with the "Add member" button:

And you can edit a team member's role, title, department, and their manager:

Remove a user from an organization via the edit options (above) — selecting "Remove member" from the three-dot menu:

Still have questions or need troubleshooting? Please use this link to submit a ticket. Thanks!