Below is step by step guide that show you how to convert iTunes AAC to MP3 on Mac OS X (including Snow Leopard) with Eahoosoft Audio Converter for Mac.
Choose the file, click "Profile" drop-down button to choose the mp3 formats you need, then click "Browse" button to choose destination folder for saving output files.
click "Setting" button to set parameters to meet your needs. You can set audio parameters contain sample rate, channels, encoder, bitrate.
After choosing the format, you only need to click "Convert" button on to complete the task.
Ok, the above is the easiest function for your conversion. the software can convert music files automatically. It is especially easy when you want to batch convert lots of files.