This zipfile contains 2 files, one is the SEF file and the other the language file.
For all files the same procedure:
1. Unpack the files
2. Copy each file to its own folder as described below
3. Empty sh404SEF cache
4. Reload your site

The SEF File
The file com_kunena.php goes to the folder /components/com_sh404sef/sef_ext

The Language file
The file com_fireboard.php goes to the folder /administrator/components/com_sh404sef/language/plugins