Select the "Settlements" tab on the top toolbar - this will direct you to:
Settlements & Negotiations
Type in the desired client in the "Contact" window and then click on the "Apply Filter" button located on the far right of this toolbar.
This will create a list of all the settlement offers submitted for this client. Select the settlement offer you wish to cancel by clicking on the green arrow icon located on the far right of the entry. This will direct you to:
Settlements & Negotiations > New Settlement Offer
Click on the "Delete Offer" link and a window will pop up asking if you are sure that you want to delete this offer. Once you select "OK" the settlement offer will be voided in the system and all settlement payments scheduled will be voided from the client's payment schedule.