I am not completely sure, so somebody else please correct me if I am wrong:
You will need to have Winamp installed. Then install the plugin (in Winamp).
Then find those installed plugin files in the relevant Winamp folder, and copy those to the MusicBee Plugins folder.
After that you start MusicBee, open the equalizer (and dsp) panel, and you click the button 'Import Winamp'.
The rest should be self-explanatory.
But be aware, there is no guarantee at all that all Winamp plugins will work in MusicBee.
(and the one you are looking at is almost 9 years old and no longer maintained)