Hi Thebhgroove and welcome to the mPV forums! :)
One way to do this would be to import your MP3 file on a stereo track, then [b]Control-Click[/b] the region and select [b]Convert to new Audio File(s)[/b]. In the [b]Save Region As[/b] window, select [b]Interleaved to Split [/b](under [b]Stereo Conversion[/b]) and click [b]Save[/b].
You will then find the 2 mono files (Left and Right) in your Project Audio Browser.
You could also bounce the whole project (with the MP3 track soloed) and choose [b]Interleaved[/b] under [b]File Type[/b]...
I hope it helps!