Rotating Background with each refresh

Hi guys,

I know this has been covered in the past, but it was like, 2 years ago.
I want to have my background image change with each refresh, but I’m not sure where or how to do this.

I’m just learning all of this, so excuse my lack of knowledge. I’ve read up on inserting a rotate.php code into the header.php, but am not sure where to insert it. I’m also unsure about the rotate.php code. However, all of this was posted a while ago…

So if anyone could give me the dumbed down, step by step version, I’d be very grateful.

Thanks in advance!