How does one change the audio files?

Question

For the most part, the tutorials I found aren't very helpful. I'm assuming it's not as easy as Brawl and Mario Kart, since I keep getting an error that reads "Object reference not set to an instance of an object" whenever I try to save these changes.

Ronoc111 · Answer

I don't think its to difficult I'll tell you how after I figure it out myself

RunninPigeon · Answer

Heres a tutorial you might find useful!