How do I remove the game from my hard disk completely?

After uninstalling the game normally, the League of Legends folder on my hard disk is still left with 6 GB of trash. I believe uninstalling should remove the game completely, not leave about 75% of its content intact. I could understand a few megabytes for user settings, but six gigabytes? I'm trying really hard to refrain from sarcastic and offensive comments towards Riot Games, so please appreciate it and provide a solution for this mess that wouldn't be pressing Shift+Delete as I'm sure some remnants would be left over in other places anyway.
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