Widgetize Theme

Im trying to widgetize a theme I downloaded recently. The theme is called gimpstyle and is available to download from here: http://granimpetu.com/gimpstyle/

The problem is when I try using the instructions on the wordpress site to widgetize the theme, it messes up all of the styles and things go everywhere.. Could somebody please explain what I need to do to make it work correctly?

Thanks!