Remove assign css while navigate to web browser in c#

Question

Hi,

When we navigate any html file to web browser like
webbrowser.navigate(new URI(<path>));
the htnl file has some css file inject then when I change the ForeColor of the document it is not effecting for <h1> tag's because of the <h1> tag include the css file.

While navigate the URI I want to remove that css inject through c# code.

Thank's in Advance.