How to add a new User at the Trust Level and set Permissions
Video Guide
Add a New User
Please Note: If you have added a user under their Organisation, they will automatically appear on your Federation User list as this is a list of all users across the trust.
To add a new user, go to Settings > Federation > Users.
If the Users option has a padlock, this means you do not have permission and will need to contact your system administrator.
Press the Add User button to see the following dialog:

Enter the new user Name and Email address, then select the permissions you want to give them by toggling on or off the roles.

Note:
The administrator role contains all other roles and will give the user full access across the whole Trust.
If the selected role supersedes another role, it will automatically select it for you.
Press Save Changes when done and the user will be created.
The system will automatically register the User and notify them by email to create a password.
If the user does not receive the email within 5 minutes, please check the email address or contact support.
If after creating a new User, you notice that you have entered the wrong name, the User can amend this by going to Settings>User>Preferences and amending their name:

If you have entered the wrong email address, simply Delete the User in question and re-add with the correct details.