How can I replace sound files?

Firstly, I am only seeking to replace some sounds with dank memes for my own entertainment. I do not want to hack this game to give myself an advantage. That, however, was a partial lie because at the sound of dank memes I gain unstoppable strength. That was a joke.

Hey everyone, total weeaboo trash here, and I am currently trying to figure out how to replace some sounds in the files with my own sounds. This, however, is quite hard considering I suck at technology. Anywooper, the one thing I want to change in particular is that I want to replace Cho'Gath's eating sound with this: https://www.youtube.com/watch?v=hVHigvYeoYw. If anyone can help me in any capacity, I would enjoy that. Bye, children.