To unassign class categories to the users, follow the steps given below:
Step 1:
Select the Concerns module and then select the Map Organization Users to
Class Categories under the Concerns menu.
(Concerns--->Concerns--->Map Organization Users to Class Categories)
Step 2:
Select the Location, Branch, User Type then click on Get. Against the respective
User Name, select the class category and then click on the Delete icon given
against that class category to unassign.