I guess we do need some fort of FAQ section for somethign like this maybe.
First of all, UNZIP the downloaded pack.
You should have one folder with up to 4 folders inside. The main folders in there you need to be concerned with are modules and themes.
Now, on your FTP, you should have a modules folder where your Nuke site is.
In there is a folder called Forums. In there is a folder called templates. In there is where your templates for your Forums go.
Now back to the pack. Remember I mentioned modules folder? Well, it's the same layout as your FTP. In the pack, in the modules folder, is a folder called Forums, in there is a folder called temaplates, in there is the NEW template. Using your FTP client, like WS-FTP Pro or Cute FTP, just simply drag and drop(upload) the folder that is in the template folder of the pack(should be the name of the theme pack i.e. charcoal) to the template folder on your FTP. Do the same with the themes folder in the pack and your themes folder on your FTP. Drag(upload) the folder in the themes pack over to inside your themes folder on your FTP.
NOW. You must ADD that template to the Forums. The theme will be automatically available no need to do anything else with the theme, other than maybe change your logo for it, which you can figure out surely at this point :?

Go to your Forum Administration. Go to Styles category on the left, under there is ADD. Click ADD then on the right you SHOULD see the name of the template if you uploaded it correctly. Click INSTALL next to it's name and your're done.
If you want to set the template and theme as the default overall theme for your site. Go to Forum Admin, CONFIGURATION and set the template there. Then go to Nuke Admin under Preferences and set it to match there as well.
Geesh I hope that clears it up.
mikem