To install the application run the file FreeConvertM4AToMP3Setup.exe.
Press the "Next" button in the first screen.
Afterwards, select the directory where the application will be installed, or simply accept the default one and press the "Next" button.
After the application is installed you can start it by clicking the Free Convert M4A To MP3 shortcut icon on the desktop or by selecting the Free Convert M4A To MP3 shortcut from the Windows start menu.