Paypal Verified Seller heading

The Paypal Verified Seller heading in left column takes up 3 lines. Would like to change it to either smaller font on just this category so that it fits on one line or maybe just have it say Paypal to fit on one line. I have tried changing the text in paypal_logo_sidebox.php but that didnt work.
define('MODULE_PAYPAL_SEAL_ALT_TEXT', 'Click to Verify');
define('TEXT_PAYPAL_VERIFIED_SELLER', 'Paypal Verified Seller');
?>

I would be very greatful if anyone could point me in the right direction please.

http://towerhousedolls.co.uk/

You should be able to adjust the font size by adding this to your stylesheet:

#paypallogoHeading {font-size: XXpx;}

RescoCCC:

You should be able to adjust the font size by adding this to your stylesheet:

#paypallogoHeading {font-size: XXpx;}

Thanks for your help.
I have looked in stylesheet.css and stylesheet_categories_dressing.css but cant find it in those.
Do you know which stylesheet I should look in please?:dontgetit

Im trying to get to grips with Web Developer but not sure how to read the results to fix the problem.
When I click Informatin - Display Element Information and click on the 'Paypal Veified Seller' logo heading it shows this info

Attachment #9841

Everything is there and I can see what I could try & alter to fix the problem but does this tell me where to find it?

Is there a forum on here with help on how to use Web Developer?

Does this mod work with v. 1.5?