Step 1: Visit FeedburnerGet the credentials form your feedburner admin, access your Feedburner account and select your Feed.
Step 2: Export CSV fileGo to Email Subscriptions menu and select Manage Your Subscribers.
Feedburner allows you to export the list in a CSV file. If you do not see this option, use our Feedblitz workaround (below). The file contains opted-in emails for your blog only.
Step 3: Deactivate Your Email Sign Up in FeedburnerOnce you’ve collected your email addresses, be sure to Deactivate your email collector in Feedburner so no one signs up here again.
OPTIONAL: Our Special Feedblitz Workaround
It is possible that you will be unable to pull the email list from Feedburner. (e.g.: you lost the login or there was a technical problem).
You should be wary of continuing to use Feedburner because Google unexpectedly discontinued GoogleReader in 2013 and many people expect Google to eventually turn offon Feedburner. Instead, switch your RSS to Feedblitz or the default RSS in your system.
The upshot of using Feedblitz is they allow you to import your Feedburner email list automatically. Once you get it into Feedblitz, download the file and follow Steps 4-5 above. Then turn off your Feedblitz email subscription.