You can delete wallet addresses directly from your account. Simply click on the wallet itself. Then you will see a list of all your current withdrawal addresses. There is a trashcan on the far right of each address. Please click on that trashcan button for any address you wish to delete as seen below.
Note 1: If you have an automatic withdrawal plan set up and you delete that address, it will cancel your automatic withdrawals.
Note 2: If you have an automatic withdrawal plan setup please delete your addresses through that module rather than the manual withdrawal module.