The Max/MSP library connects to the Gainer I/O Module through the serial connection. There are two types of files in the library, .help and .pat. The .help files explain how to use the Gainer I/O Module, while the .pat files carry out the actual communication with the module.
Unzip the files to your desktop. You can open the files directly from your desktop after they have been unzipped, but they should be installed in the appropriate location to work correctly.
Place the .pat files in the following folder: MaxMSP4.6/Cycling '74/externals/gainer/
Place the .help files in the following folder: MaxMSP4.6/max-help/gainer/