The fonts are in the downloaded folder, and all you do is drag and drop them into the Font Book, which is the font application for mac. Font book is in the application folder, so open it up annd drag and drop.

Hope this helps.

doesn't work for the beta, any reason why? (all the other xtras seem to work with the beta)

i could chanage to the normal adium version, but this one is a lot better :P