Seems Simple But Not...Change A Class Attribute(?)

[jerkin.slow]

Greetings: See this page: www.abacuscustompainting.com

Specifically, this highlighted section (see attachment)

I'd like to:

1. center the two sentences at their current location on the page
2. place the second sentence in its own paragraph
3. increase the font size of each sentence

But I understand the attributes for the text in question are controlled by its class? Is that accurate? If so, wouldn't modify this class's attributes impact text elsewhere on the website assigned to that class? Regardless, could someone tell me precisely how to accomplish my three objectives w/o impacting the governing class - sitewide?

Thanks in advance...