Topic: font size etc

I'm an absolute newby so please bare with me.

I have purchased the pro and want to change the font size and type but I can't get it to work. I tried both the index.html and the gallery.xml to enter it but it stays at the default.

I see my images map, gallery.xml, index.html, swfobject.js and viewer.swf
Where should I edit my font data?
These files have been exported out of Lightroom. in which I see no possibiltie to edit these data.

regards,
Frenk