Through the user management settings you can give team members or partners access to your Steam Data Suite account. In Steam Data Suite go to the configuration page by clicking the cog icon on the left bottom of the main menu. Click Users in the top bar to go to the user management page.
While editing a user you can choose whether or not to grant them Admin permissions by setting the checkbox. A user with Admin permissions is allowed to create and edit users too.
If any of your teammembers forgot their password you can help them via the Manage user screen. Find the person in the list that needs a password reset and click the Reset password link. They will receive an email that allows them to set a new password. A forgetful individual is also able to reset their own password by clicking Forgot password from the login screen.
If you want to remove a user's access to your account find the user in the list and click the dirtbin icon. After confirmation this will remove the user. Adding the user again, with the same email address will restore their account.