In iTunes, go to your playlists. Select the playlist and go to File > Library > Export Playlist. Save it whereever you want an then repeat for all you other playlists…
I personally don’t do this, I instead backup my entire iTunes library onto my network file server.. If you then load up that iTunes library that you have backed up then you can then see all the tracks in them and restore from there.. It is much easier however just to have a full backup of everything – to the point where if it corrupts you can just delete the corrupt data and transfer your whole backup onto the file system of your mac, and it should then just work as if nothing had happened..
Another option would be to use the playlist export facility in your chosen DJ software… That will probably be easier than fighting iTunes all the time 🙂
bob6937