Fuck it, instead. Just open the game, and use the "Open osu! folder" This will open the osu! folder (Self explanatory)
Then close the game.
Then delete your osu!.pcname.cfg file. (If File extensions are disabled it will be "osu.pcname" and will be a configuration type file.
OR
Click the yellow bar next to every option in the game, or the one you think you messed up, and it will reset it to its default setting.