Again, pick a song from the Low Intensity list, such as Queen/Daft Punk and play on the Hard difficulty setting. The Achievement is not dependent on any effects knobs, fader moves, or button taps, so just focus on the scratches. Of course, if you hit a scratch that incorporates the fader (the scratch "bends" in its lane) you will need to perform that fader move for the scratch to be considered successful.
The Achievement will unlock once the mix has completed.