Okay you want the second attachment 324.
Because the one you have now is a little outdated for your version.
Download the zip file and extract it.
You will have two folders and a txt file.
Add the two folders and contents to your site using ftp.
So when you connect ftp goto forums/styles/images
Upload the two folders with contents there.
Then goto cp>styles and select import style.
You will then be prompted to brows to a file. Browse to your computer where you extracted the zip file and select the ubbcentral_with_wrapper.txt file. And import it.
It will add that style to the control panel to use.
