I suggest you just follow a phpRetro tutorial, its near enough exactly the same.
Change the config.php folder to link up with your own SQL database or just put the install folder from phpRetro in their and remove config.php from includes.
It is his first time, he doesn't know how to install it like a normal hotel, and if you actually read the thread then you would have noticed I have already said that.
Also, if that doesn't work then try googling your problem. Always works for me