CSS: How to remove pseudo elements (after, before,…)?

I would like to use a switch for the layout of paragraph tags on a webpage.

I use the after pseudoelement:

p:after {content: url("../img/paragraph.gif");}

Now I need to remove this CSS code from the page.

How can this be done easily?

I want to add that:

• jQuery is already used on the page

• and I do not want to include or remove files containing CSS.