[Zubersoft]

You can long press the song on the library screen to select it, tap the three dots at the top right, then tap "Swap File" to swap in the new version of the file. Alternatively, you can just use Import->Local File and when prompted with the conflict, select that you want to update the existing song (this only works if you let MobileSheetsPro manage your files). Another option is to just replace the file in the storage location used by MobileSheetsPro (Settings->Storage->Set MobileSheets Storage Location).

Mike