Im not at home at the moment, basically all you need is the files,
Create a folder in your root, vatstats or something, then in that you need another folder vatsimphpfiles, in there you have blank text files for airports.txt customization.txt,metars.txt,satnet-data.txt and status.txt, make them all 764 (permissions).
Then you should have the following files in your vatstats folder,
all.php
vatpilots.php
vatsimnow.php
VatsimPHPgenerator.php
To display on your pages, just do an include or iframe,
So,
<iframe id="Vatsim" src="http://yoursource.com/vatstats/all.php" width=680px height=300px marginwidth=0 marginheight=0 hspace=0 vspace=0 frameborder=0 scrolling=yes></iframe>
These files All can be customized to display your callsigns only or everyone on vatsim.