Open Constant Contact and click Contacts in the top menu bar.
Check the contacts you want to export and the Export button will show up in the dark gray toolbar above your contacts.
If you'd like to export all of your contacts, click the checkbox in the top row. This will select all of your contacts.
When you click Export, you will be asked which information to include in your export. Check everything that's relevant.
A pop-up will offer you a CSV and an Excel download.
Download the CSV file.