I would think that disabling the CSS on the page should do what I think it is you are asking for.
In Chrome you can do this in the developer console:
- Bring up the developer console by either hitting F12 or navigating to it
Menu --> More Tools --> Developer Console.
- Within the developer console browse to the Sources tab. In the top-left corner of this tab is an icon with a left facing arrow. Click on it.
- Browse to the css file you want to eliminate. Start at the Network layer and work down, seems to work best. Highlight all of the text and hit delete.
- Remove stylesheets until getting the result you want.
This stackoverflow article has other options as well as this:
How to disable CSS in Browser for testing purposes