This tool is meant to prepare a firmware to be loaded in a Teensy 2.0 board. Just unzip the package somewhere handy. Make sure you have a Java 1.6 (or more recent) installed on your system. The tool has a built-in "teensy loader" that will recognize the Teensy through the USB port. Alternatively, the Teensy Loader software may be used to upload a .hex file generated by this tool.