Download and install the audio-editing program Audacity. It can be found at their main website. There are versions available for Macintosh and PC.
Click and drag your 32-bit audio file into the main window of Audacity. This process will automatically analyze your file, determine the sound quality and import it into the editor for editing.
View the list of options in the "Edit" and "Effects" menu. Read the documentation on Audacity to learn what each function does, and begin editing your audio file as desired.
Export the audio file using the "Export" menu. This step will allow you to choose from several different file types and change your song from 32-bit to another higher or lower quality song format.