Yes you need to know some html and basic copying and pasting of code. Path structure for linking to images or internal links that may or not need changed to make a matching theme. You are basically forcing the Nuke theme to use the same grpahics that the Forums use. and the same color scheme and css styles. Bothg have their own images, colors and style but you just need to edit some code(css) and copy images back and forth to make a clean look.

Basically this is one of the main things this site does, makes nuke themes to match to a phpBB Ported Forum template.
However explainging every single step you would need to take to complete this task would take quite a bit of typing...not sure if the 'ole Carpul Tunnel would be too happy about it

mikem