Delete or modify playlist names

It would be very nice to be able to modify and delete playlist names. When I started, I thought to use a certain standard for some of my playlist names, but later realized the way I was naming them was redundant. I've fixed that, but I now have a number of empty playlist names I no longer will use, and the auto-fill continues to consider them when I favorite new songs and save them in playlists. Also, if I could modify the playlist names, the change could take effect on all songs in that playlist rather than having to edit the playlists for each individual song separately.