You need to download it and save it as an MP3 or whatever, then find which is the audio for the openeing screen, proably by just playing them over and over, then rename it to what the original was, and voila!!
Also, there are multiple starts, so you gotta find them all and rename them.
As for replacing the startup songs with this you could either look on google to try and find an answer or just go into the files and look around for the startup song files and replace. I know i would stay on the startup screen longer if this were my startup song lol.
The drums were awesome, it makes me crave a double kick for my kit now...Has lots of power in it. Very TF2ish, but I think they'd write a whole new score for TF3 (if TF3 will ever come out, which I hope it doesn't)