Help adjusting sidebar widths (zeke 1.0 theme)

Hi,

Please view my blog at http://nybodyboarding.com/
I am running wordpress 2.5 and using the zeke 1.0 + widgets 3-column theme

I would like to expand/widen the far right sidebar so that the current 300×250 ad banner fits inside, instead of overlapping the border as it does now.

In order to make the far right sidebar a bit wider (+50 pixels or so), I would like to shrink the middle sidebar, making it narrower (-50 pixels or so).

I attempted to do this in the stlyes.css file but didn’t have any luck.

Any help is greatly appreciated in advance.

Kind Regards,

NYBB