I just joined this community and discovered a cheap dlc of South Park Theme http://store.steampowered.com/app/369766/ for 0,99€ that you can use for your necessary one DLC. One little problem ist that there's no such DLC in RocksmithToolkit, so I added it there and it works just fine :) Only thing you have to do is download this file here: https://drive.google.com/file/d/0B2H9fHLo13-iZEd1cWQwREdwZG8/view?usp=sharing and put it into root folder of RocksmithToolkit and rewrite. It will just add this one DLC to the library. ...and then just continue as usual with the toolkit :) EDIT: or instead of downloading that file, you can just put this number as App ID: 369766