Quote: "Now what do I do with it? I'm not the sharpest tack in this box, so any and all assistance would be appreciated!"
Locate your Dark Shader folder and look for the file Preview.exe. Rename that as something just in case you need it, e.g. PreviewOld.exe. Then unzip the download file - it should contain just the one file, i.e. the updated Preview.exe file. Just place that in your Dark Shader folder. When you run Dark Shader it should now use the new Preview.exe file.
One thing to note is that the documentation says it no longer supports PS1.x shaders. No idea why (and I haven't tested it to see what happens) but that shouldn't be a problem since you should really be using PS2 upwards now.
Quote: "Tried the update the preview window is white, And nothing shows up.
Try and add a model no loading box comes up."
Did you backup/rename the old Preview.exe file? Are you sure you've got the file Preview.exe in the Dark Shader folder? I can reproduce exactly those symptoms by removing Preview.exe from the Dark Shader folder.
I see you're using W8. I haven't used that yet but I wonder if that's an issue here and perhaps W8 is preventing the new Preview.exe from running?