I'm designing a relatively simple site for a friend. I would like to impliment php so that he can change his header/footer without having to go back through every file. Problem is, I'm pretty much totally unfamiliar with how php works. Is there a simplistic way to do this? I've seen a few answers for how to make a php header but they all seem different and I haven't had much success. I'm not saying they don't work (I probably did it wrong) but the simpler in this case, the better.

Thanks!