Need Regular Expression

Hi,
My requirement is add a style sheet in to web page insted of existing styles. to do that, I need to remove all the existing styles. It is difficult. Then I found a tool notepad++ to remove existing styles. There are many types of styles. Some styles are multiline
Ex-
<td style="border-top-width: thin; border-left-width: thin; border-left-color: gray;
                    border-bottom-width: thin; border-bottom-color: gray; width: 115px; border-top-color: gray;
                    height: 26px; background-color: whitesmoke; border-right-width: thin; border-right-color: gray"> 
 
and some are in single line. I foundout this this can be achieve useng regular expression because if it can track style=" ...