Follow these steps to add multiple Discounts to an Individual Payment Plan (NOT a Payment Plan on an Enrollment Period, but one that is customized for a certain Enrollee).
Step 1 - Find Enrollment Card/Payment Plan
On the Enrollee's Billing page, scroll down under "Tuition/Active Enrollments" to the Future Invoices and Payment Plans box. Click on the Edit button.
Step 2 - Add Discount
Under Scheduled/Installment/Subscription Payments, click the blue dollar sign beside the Charge Item (i.e., "Class Fee") to add the Discount.
Step 3 - Edit Discount Item Name
Edit the Discount name by clicking the pencil icon.
Step 4 - Add Amount and Save
Add the amount of the Discount and click Save.