To export the entire subscribers list, go to "Subscribers" (1) and then click on "All subcribers" (2). 

After that, a list with all subscribers opens. Scroll to the bottom of the window and on the bottom right corner click on "Export contacts".

A CSV file will be downloaded with all the info of the subscribers.

You can also export lists separately. For that, go to "Subscribers" and click on the name of the list you wish to export. Do the same as for all subscribers - scroll to the bottom of the page and click on "Export contacts".