Change Column Width in Fixed-Width Theme

I have a website I’m building. The theme I have is a fixed width theme. I need to extend the width of my content column or decrease the width of my sidebar because my content is goin over my sidebar.

I have changed many values in my style.css file, but can’t seem to accomplish what I want. I also can’t find a suitable answer on these forums. How would I go about changing my column width? Thanks

My site: http://www.remembereddreamz.com/?page_id=185

Theme site: http://ww.wp.xz.cn/extend/themes/color3