Hi MeganJoan
This is the link I used. It downloads the kobo software, not the useless borders app we know and love...
http://download.kobobooks.com/desktop/58/KoboSetup.exe
You don't actually need to log on to the kobo app for the firmware upgrade, which is good. Have a look at a few other threads here for any potential pitfalls.
The upgrade fixes the font scaling and a few other things, but does introduce an autopowerdown function which many people (including me) find extremely annoying. Your call!