Change website header to 100% width must match header image

Hello, I would like to change the top header in my website to 100% width. There is an image in the center of the header and I would like to have a small repeating image extend to the left and right of that image. The smaller image and the original header image must blend perfectly. It may require different images to the right and left of the header or possibly editing of the original header image. Please see attached. This will have to be done with CSS. I would like to see a mockup image before any coding. Expertise in Photoshop and css will be required.