Serious Sam 2 Renovation Cecil Fight but it's As Above, So Below

(Excuse the quality of the video and my gameplay I forgot how the jump boots and Cecil worked). I changed the Music from the shortened version from Second Encounter to the actual song by Undercode, and It works really well with the latest Renovation to feel more modern. All I did was go to All_PC_03.gro, open archive with 7-zip, Content, went to music, then boss, then replaced the original with this but with the exact same name as the original file. I think you can do this to all of the music if you know what you are doing. I'm gonna see if I that is true.