A server is just a computer like the one you're typing on. Websites are just collections of files sitting on the hard drive of that computer. Generally people get files to and from their server using FTP, which is just a type of program that lets you copy a file from one computer to another over the internet. There's no specialized knowledge needed to understand that much of it. Apologies if I'm saying something you already know.
Give your new programmers the FTP login for your web hosting and they'll probably be able to find the right file.