I don't know you personally but from the two threads I have seen from you arised one question: Why does he want to do this this way (don't take it personally, this was just my two cents)?
But for your question: I know no easier way than to simply put the id/class in the search and replace field (like the person in the second post wrote) and then overwrite it. Example "<p class="whatever">" with "<p>". Don't forget that you need to be in the code view for this and that you need to check "in all HTML files" (is a drop down menu).
As said I don't understand why you want this but everyone has their preference. For example: How are you formating bold or italic text? In the HTML? Wouldn't it be easier to define a class and use it? If you remove all classes you get virtually everywhere the same formating.