Editing a website,  especially a CMS based site thay had a theme and CSS in for example WordPress it can be hard to do, getting the look and feel you really want is diffucult and you may feel restricted to what the theme has to offer.  Powerful tools either are included in modern browsers or can be added to them to allow you to inspect elements of a website and play with the look and feel without changing the website code directly.

Firefox has a nice extention you can install called Firebug, by inspecting an element it gives you control of what drives the look/feel of a website such as the  CSS.  If, for example a logo or image is not where you want it, you can right click it and usually there is a menu item to inspect Element, you can then change parameters of that element such as positioning until you have something you like,  you can locate where in the CSS this is them controlled and go and make changes to the code of the site making the change permanent,  its almost like vitual exploratory surgery if a website.

I use these tools when working on WordPress sites to disect a theme and customise it to be more to what the customer wants when they come to us for a web design project.  Islandnet.com can be hired to make changes to your site.