1) you must choose an AUDIO track on the arrange page
2) got to the AUDIO tab at the tops of the screen and choose IMPORT AUDIO
3) once the audio is imported you must go to the MIXER windoe
4) go to the master fader and hit the BOUNCE key
5) on the menu you will have the option to choose SPLIT L/R or interleaved
6) choose Split there fore taking your stereo file and splitting it into 2 files