autoconvert names to links

I know there is a WP-people hack, but I don’t want the names linking to some profile, I want it to link to their site. So I tried this tutorial on how it’s done in b2 (https://www.cafelog.com/board/viewtopic.php?t=1145&highlight=convert+friends+names+links) but I messed stuff up terribly because I don’t know where the heck I was supposed to be inserting those functions. Does anyone know how this is done?