CSS Stylesheet Edit...

This may be outside of your support, but I thought it wouldn't hurt to ask! I'm using the wordpress theme Yoko by elmastudio. I've tried lots of themes, but this one best suits my needs in terms of use and appearance. There are, however, two things I'd like to change about it and after hours of staring at code, I've still been unable to do so. (I don't know anything! about CSS except that it moves things on my page.)

my site is terrysloan.com, if that helps.

What I'm trying to edit:
I'd like to move my main navigation menu to below my site title (& that grey line!) I'd like my sidebar 1 to be wider.

Thanks in advance, if you're able to help, if not, thanks anyway!
Melanie