Click "ADD USER" to add users to the dictionary.

Click this checkbox to select your collaborator.

Choose 'Role' for the selected user, by default is 'Contributors'.

Click "ADD SELECTED USERS" button add the user to your dictionary.

Issue: Remove role not functional for the current version (Beta-v1.0.1). 

After adding a user, you could change their role anytime by clicking the user item in the list of users. 

Click "ADD ROLE" button to add a role to the user.

Select the role you want to add to this user.

Click "ADDROLE" button to finish this action.

You could remove a role for a user by simply clicking the "-" remove button.

User management - Semantics4BIM