Here's how you can disapprove an affiliate:
From your dashboard, go to Affiliates (left-hand menu) > Click on the affiliate. This should open the details panel on the right-side of your screen. Here you can see the programs the affiliate is a part of as well as their status within those programs.
To change an affiliate's status, click on "Approved." This opens a drop down menu that includes the option to disapprove the affiliate.
Please note that disapproving an affiliate from a program is not the same as deleting the affiliate. When you disapprove an affiliate, their information is archived. When you delete an affiliate, their data is permanently deleted.