If you dont know where that is just open the start menu and click run and type %appdata% and click .minecraft. Then click bin, add then click minecraft and click open with winrar archiver and drag and drop the terrain into winrar.
The only changes are glass but more are on the way.
Make your texture pack into a ZIP file like a regular texture pack, I'll consider looking into it then. Also, edit the minecraft.jar only for mods. nothing else.