Question

I Need A Page Action Or Browse Action with Files That Change An element In A Website

Answer 1

take a look at this: http://code.google.com/chrome/extensions/content_scripts.html

You can add javascript scripts and css stylesheets to a page to change the content.

good luck!

an example to change the background of http://www.google.com:
you create a .css file with:

body{
  background-color:black;
  }

when you made the .css file, add this to manifest.json:

"content_scripts": [
  {
    "matches": ["http://www.google.com/*"],
    "css": ["[name].css"]
  }
],

matches means it will be added to any website that begins with http://www.google.com/ because of the ‘*’.