How do I install nodification files

I would suggest you spend a bit more time writing your questions, so people can tell what you are talking about.

If you are referring to MODIFICATIONS or MODS, these come with whatever instructions the author has provided.

Although based on some of your prior questions I would assume you are not knowledgable of PHP and possibly advanced HTML.

Installing most MODS (at least advanced ones) requires some of these skills to a limited level.

Some Mod creators offer installation services either with the purchase of the MOD or as a extra service.

CyberXing