edit css

Dears, I'm new on this forum and on editing joomla (gavick) websites in general by using css.
How do I change for example the message on the blackboard starting with welcome !
followed by "Sed ut perspiciat unde orodiaer leroacustiu mera reuentis mose keriasertas toresa.Architecto beatae naseaeraciat kuiase undeosler miase osac usa ntiume uedearsteked icexplicabo nemo enim ipsam lertasevol uptatemia voluptas sit."
I can't find this item in the articles,...
How do I change the text on the blackboard underneath ??
General opening hours:

Monday - Friday
from 11:00am to 10:30pm

Saturday and Sunday
from 12:00am to 3:30am


Please explain it in easy language for me if possible ??

Thanks for helping me out !!

Ivan.

I found something with firebug in mozilla firefox . I changed the text but after this I can't change anything in firebug itself. Is there a save-button or what did I do wrong ?
thanks for your help !!

Hi Ivan,

I've fixed them for you.

Cheers,