How to change picture on forum

[Grumf]

English:
Hi everybody.I need a litle help....I using Snow blueby Mytheril theme for my forum,and i don't know how and where I can change i litle picture on home page (picture with text "Snow Blue")?
A want to make a personal theme,but I am new,and I need a help to learn me how to do it.Thank you everybody.

Serbian:Caosvima.Moze li neko da mi objasni kako i gde da promenim sliku na mojoj temi (Snow blueby Mytheril)?Slika se nalazi u gornjem delu foruma sa tekstom "Snow Blue".Relativno sam nov i zeleo bih da napravim svoju temu,da nebi tudju temu prepravljao(nije u redu prema autoru),pa ako bi me mogli malo uputiti,bio bih vam zahvalan.Znaci trenutno me zanima samo ovo:Kako da promenim tu sliku u vrhu teme.HVala svima unapred.

[Nessa]

Hi, your title not being specific and therefore not facilitating research via the search option, I'm not answering (nor is any other member ) until you change your title to a more specific one, related to your problem