How to mix audio files with DRM protection?

You cannot mix directly DRM protect files, since DJ software cannot load iTunes DRM protected files, so the solution consists in;
- burning the DRM music files you buy on a CD audio on the computer on which you purchased the files (it means you need a CD burner on the computer where you buy music files with DRM, for example in iTunes),
- and afterwards either mixing the CD audio in your DJ software if your DJ software plays CDs, or extracting first the CD-audio tracks into MP3 files to mix them in your DJ software.