1- Click on “Playlists” in the left vertical menu. This will load all the playlists added in the Library. Click on Manage to see your created playlists.
2- Click on the playlist that you want to edit, under “Your Playlists”. Click on Edit option.
This will load the Edit Playlist page as below.
3- To share your playlist publically, enable option 'Allow External Access'. You can share url of your playlist with anyone to share the playlist publically.