Click on the "Activities" tab of the main menu options.
Click on the activity to which you will assign a user.
In the Overview tab, scroll down to the bottom section: Staff Roles.
Click on the first empty cell under "Person" and a dropdown menu will appear. Select the user you want to assign to this activity.
Optional: In the "Role" column, add the role the user has for this activity. This might differ from their formal job title.
All changes are automatically saved.