[TYPO3] CONTENT - remove all CSS styles inside

[Karol Martinka]

Hello,

I've written this code :
subparts.CONTENT_STORY_IMAGE = CONTENT
subparts.CONTENT_STORY_IMAGE {
table = tt_content
select.orderBy = sorting
select.where = ((colPos=0) and (CType='image'))
}

It is intended for a page, where on the beginning should be a image, which 
has to be placed as a content element on page.  So far, so good, it works, 
but I would like to know, how to remove the CSS styles from this object, 
please? TYPO3 adds lot of CSS overhead, but I do already have my own styles 
on the page and for this particular image(s), I reallly don't need the style 
wrapper :((.

Btw. I really don't understand the concept, why Typo3 and all of the plugins 
have own styles, and where can I redefine the styles or even remove some 
unwanted formatting...

So if you may have any good article about CSS styles in TYPO3, how to remove 
or edit them and how to clean-up the site, just let me know, please!

Thanks,
Karol