1) Click 'Customer Reports' under the 'Reports' heading of the 'Control Panel'.

2 & 3) Search for your customer & click the 'Submit' button.

4) Find your customer in the search results and click the 'Edit' link.

5) Click the 'Mailing List' tab.

6) Check the box next to 'Please add me to the mailing list.'

7) Click the 'Update Customer' button.