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When you have finished downloading, use StuffIt Expander  to extract the files (this may happen automatically), then save the file called "LameLib" or "libmp3lame.dylib" anywhere on your computer.

There are several ways to expand a compressed file with StuffIt Expander. Try the following:

• Double-click the icon of the file. On many systems, StuffIt Expander will launch and expand the file.
• Using your mouse, click and hold the icon of the file, then drag it over the icon of StuffIt Expander. When StuffIt Expander's icon darkens,release the mouse button. StuffIt Expander will open and expand the file, and then quit.
• Double-click StuffIt Expander's icon, and wait for it to open. From the File menu, select Expand, and in the window that appears, find the file want to expand. StuffIt Expander will then expand the file.
• With StuffIt Expander open, from the Window menu, select Drag Window. To expand your file, drag it into the Expander window that opens.

HINT: If Stuffit won't extract the downloaded folder, try Zipeg  or BetterZip  for zip folders or Springy  for .zip or .sit folders. Or if you use Audacity 1.2.5 for Intel or Audacity 1.3.3, you can download an already unzipped copy of libmp3lame.dylib . If clicking that link only gives you a page of characters in your web browser, go here , and scroll down to "libmp3lame.dylib". Then control-click over the link and save the file to your hard drive.

Then do as follows:

1. Launch Audacity, click Audacity > Preferences and go to the File Formats tab. If this is not visible, click on the left-pointing arrow top right of the window
2. In the bottom of the window there is a section called 'MP3 Export Setup'
3. Click on the "Find Library" button
4. In Audacity 1.2.5 or 1.2.6, this will ask you if you want to locate the LAME encoder. Click "Yes". In Audacity 1.3.3, click "Browse".
5. In the dialogue box, go to the folder where you put the unstuffed "LameLib" or "libmp3lame.dylib" file earlier, and select it.
6. Click Open, then OK

In the same "MP3 Export Setup" section, you can then in Audacity 1.2.5/6 set the bit rate of the exported MP3 by clicking on the downward pointing arrow in the "Bit Rate" dropdown. In 1.3.3 Beta, the MP3 bit rate is chosen when you click File > Export and choose MP3 in the "Save as type" dropdown; you can then click the "Options" button to choose the MP3 bit rate in the "Quality" dropdown. The default bitrate is 128 kbps in both versions of Audacity. A higher bitrate gives you higher quality at the expense of a larger filesize, and vice-versa. A 128 kbps bitrate takes up about 1 MB of space per minute.

In 1.3.3, the "Options" button also gives access to more advanced MP3 encoding options as follows:

1. Bit Rate Mode (Variable, Average, Constant or use a Preset)
2. Encoding Speed (with other than constant bit rate encoding)
3. Channel mode (currently Stereo or Joint Stereo ).

Constant bit rate with stereo channel mode is always used by Audacity 1.2.5/6. Variable bit rate tends in most genres to give higher quality for the same bit rate.

Additional encoding options such as higher quality algorithms are available by choosing "external program" in the "Save as type" dropdown when you export as MP3, then specifying the relevant commands to be passed to your MP3 encoder e.g. LAME in the dialogue box.