Insert custom songs in Guitar hero III?

Hello. I have watched some guides on youtube about inserting new songs in guitar hero III with "songlist editor".
I have download the program + the torrent "Guitar Hero 3 PC Custom Pack With Guitar Hero[Snakkii]".
When i open the DATA>SONGS folder, the songs should have the .ogg format because thats the only format the
songlist editor is compatilbe to but my files are .xen format so i can´t add new songs into songlist editor because it doesn´t supports that format.

I have also overwrite the ordinary DATA folder with the DATA folder that was in the torrent "Guitar Hero 3 PC Custom Pack With Guitar Hero[Snakkii]" as the readme dile say.

What should I do?

thanks/Svante