Click on Allow
Click on Continue
Click on the Facebook icon.
Authorize Yahoo in the Facebook pop up and then wait a few seconds. You’ll see a confirmation screen like this
Ok, you’ve now imported the names and email addresses of all your Facebook friends into Yahoo. Now just click “tools” in Yahoo mail and export. CSV format is a good format for uploading to Gmail or your desktop contact book. Save the file to your desktop, and you’re done.