Change font size for home page heading and slider size?

I am using the BlackBird Pro Responsive Theme version 1.9.3 for http://www.steril-aire.co.uk/

How do you change the font size for the home page heading?
How do you change the slider size currently 950px wide-390px heights to 950px wide-310px heights

Thanks

​

 

1.For your first and second issue

Paste this code in Custom CSS
Appearance > Theme Option > Styling Option > Custom CSS

Code:

.content h1 {
font-size: 20px;
}
.flexslider .slides img{
height:310px;
}