Edit brought 'Responsy WP' Wordpress theme

Required as soon as you can - we're a new start up business.

We already have a wordpress theme and we've just brought a new theme from pixelwars called Responsy WP.
We have login details for the theme forums and help pages.

We want 2 changes making;

Change 1
The theme is a responsive theme so changes width depending on screen width, but its too wide. We want to bring the max width in by inch/inch and half each side.

On the forum it says to do this;

In bootstrap.css about line : 734 remove the block starts width @media (min-width: 1200px) {
this way your layout will be max 960px width even in high resolution desktops.

Change 2
We would like a white background or white texture adding to the middle of all the pages with a slight dropshadow. So we can add a pattern background to the sides and header.
This needs to reduce/lengthen automatically if we shorten/lengthen the pages.
The footer is to stay as is.

We've been told it's CSS editing but we haven't the time to do this.

The must be kept totally editable as there are a lot of settings in the theme we like to change regularly. Such as the back ground image is really important as we like to change this depending on season etc.

FTP details/logins available.

Need someone who ideally speaks good english.