How Do I Change Cat and Title Images?

[shadowsplicer57]

Alright, so I'm not entirely sure if this is the right spot to post this, but here's my problem: So I recently changed my forum skin to this one I found on OCgfx.
overcomersgfx.proboards.com/index.cgi?board=sfc&action=display&thread=672
Image of how the end result is supposed to look with the images:
http://img./v638/TheHarbor/pre-1.png
Now, said forum skin has various images that make it look awesome, only trouble is, I have NO IDEA at all where I am to put them. Those images can be found below with their labels simply as Cat Image and Title Image.
Cat Image

Title Image

So does anyone know where I have to put them?
-ShadowSplicer

[Ara (Crow)]

<STYLE type="text/css">
<!--
body

.titlebg
{
background-image: url(http://img./v638/TheHarbor/Resurrection/cat.gif);
background-repeat: repeat;
}

.catbg
{
background-image: url(http://img./v638/TheHarbor/Resurrection/title.gif);
background-repeat: repeat;
}

-->
</style>

I inserted the images already, place this in your global headers.