To export the contacts in your address book, sign into your account and go to My Account > Address Book. Click the export tab and click the link to download your contacts as a .csv file.
Your unsubscribed contacts will not be included in this file. To view or export your unsubscribed contacts, click on the unsubscribed tab.
Note: If you re-import your contacts using your export file, the "notes" data will not be imported.