no problem Ober, no need to be sorry we all start from somewhere. As for running the install.php, basically first you have to upload it to the folder that the instruction gives you. In most cases, the install.php file of the mods/hacks goes in the /admincp folder of your forums. Once you have uploaded the file and made all the file edits in the instruction, just go to
http://www.yoursite.com/forums/admincp/install.php and follow the instructions again from there.
by running install.php it means to just simply go to that page and it should do the install automatically for you,
good luck.
I think he is installing some kind of arcade hack/addon Xtrato by looking at the example code he has given, not sure though.