To unassign a SonicWall Cloud App Security license
Navigate to Configuration > Licenses.
Click the green checkmark in the License Assigned column in the row for the user for which want to remove their license. The checkmark will change to a link labeled Assign.
Repeat this step for each user for you want to remove their license.
In the upper right, under the bar graph showing the number of licenses used, click Save.
If you are assigning licenses to your entire organization, and not using Group Filters, Cloud App Security will attempt to use all of your available licenses. For example, if you have 100 licenses and 200 users, and unassign licenses for 5 users, the next five users alphabetically who did not previously have licenses will be automatically assigned one.