your header background is here
http://garibaldi-gay.com/wp-content/themes/green-apples/images/green-apples.jpg
create a substitute image - if you name it the same, you can upload it to same spot and not mess with code
if you name it something differently, you will need to reflect the change in your theme's header.php and style.css
look in your theme's style.css to adjust stuff in the header
#header {
background: #fff url(images/green-apples.jpg) no-repeat bottom right;
border-bottom: 1px solid #a8b772;
}
#headerimg a:link, #headerimg a:visited, #headerimg a:active, #headerimg a:hover, #headerimg h1 a:link, #headerimg h1 a:visited, #headerimg h1 a:active, #headerimg h1 a:hover {
font: 700 40px Verdana,Tahoma,"Lucida Grande",sans-serif;
color: #a8b772;
text-decoration: none;
background: transparent;
}
.description {
font: 600 1.5em "Courier New",Courier,serif;
color: #999 !important;
}
back up file always