1) Download FontResolutions.xml (http://lnishan.atwebpages.com/FontResolutions.xml)
2) Right click on FontResolution.xml to open with notepad, Ctrl + A, Ctrl + C to copy
3) Download RAF Manager (http://www.sendspace.com/file/vrgt4x)
4) Extract to wherever, run RAFManager.exe
5) Scroll down on the left column, and locate 0.0.0.91
6) Expand and navigate to /DATA/CFG/defaults/
7) Double click on FontResolutions.xml, a text viewer window will be opened, Ctrl + A, Ctrl + V to replace
8) File > Save to archive, and exit RAFManager

Now run LoL to see the effects!