How can I rename an audio clip when importing?

Hi,

When I receive a batch of files from our audio guy they are usually named with whitespaces and non-english letters. I have made a method that renames the files, but I cant seem to get it working with the postprocessor. Does anyone know how I can rename a file in the postprocessor?

  public class AudioPostProcessor : AssetPostprocessor
  {
          public void OnPreprocessAudio()
          {
              assetPath = FileUtil.ReplaceSpaceWithUnderscore(assetPath);
              // Try to rename file

          }
     }