How do I switch to other language VOs in game?

You can't switch the languages to not-Riot regions. Anywhere that needs a different client installed to play is a no-go. That said, you can get all of the languages that the current client supports by modding your regions.txt file.

You can find regions.txt in this folder: C:\Riot Games\League of Legends\RADS\projects\lol_patcher\managedfiles\0.0.0.0

Just add one of the other languages next to na and save. You'll then be able to select it from the menu in client. This will change all of the language in the client though, not just the voice overs. You can't change that by itself.

http://apollo-na-uploads.s3.amazonaws.com/1419196524383/Untitled.jpg

who the fuck downvoted this?

"who the fuck downvoted this?"

はじめまして

who the fuck downvoted this?

私は長い間日本の言語を取得しようとしてきましたが、何らかの理由でそれを使用できません