He didnt say get the addon he mentioned there is a way to override game fonts without one. Clearfont happened to have it in the readme and there is a useful link in the mod description for doing this as well.
Snipped from the previously mentioned link for those interested:
Code:
This part overrides all the remaining WoW fonts - including the login screens!
* Create the following folder:
o <WoW directory>\Fonts\
* Create four copies of the font file of your choice, place them in the
above folder, and rename them to the following names:
o FRIZQT__.ttf (the main UI font)
o ARIALN.ttf (the normal number font)
o skurri.ttf (the 'huge' number font)
o MORPHEUS.ttf (Mail, Quest Log font)
I did this myself ages ago and it works nicely.