Update search facility on PHP website

I have a search facility which is currently not working properly. I need it to be replaced by Google CSE on a webpage written in PHP. I believed this to be a simple request, and have the Google CSE code ready in HTML, however I do not have PHP experience.

The search is used to browse a directory listing of suppliers for a horse/livery website and return the results found. Google CSE appears to work for this well, however I am unaware how to use this within PHP.

Please bid to complete the work ASAP. Further information available on the website URL available upon request.