Hi there, I’ve just done this on my test site using the following css, remember though to upload your own images into the slider first, making sure they are at least 2000px wide.

To make the slider full width

#slider {
height: 400px;
width: 2000px !important;
margin: 0 0 0 -50%;

To move the right arrow closer to the edge of the page

.nivo-nextNav {
background: url("images/nav_right.png") no-repeat scroll 0 0 rgba(0, 0, 0, 0);
height: 40px;
left: 1153px;
width: 40px;

End result – http://screencast.com/t/kSQFslch4J