cyberchef, I think you're reading too much into Lynne's article.. it's actually a very easy 2 step process- you can ignore the "Who's online" instructions, they aren't necessary, just a little extra but not needed.
There are only 2 real steps...
Step 1. Make a new php file...
Use a text editor and make a new php file, call is test.php and copy and paste all the code below into the file and save it. Once saved upload it to your forum directory, the same directory where showthread.php, forumdisplay.php and the rest are.
The code:
<?php
// ####################### SET PHP ENVIRONMENT ###########################
error_reporting(E_ALL & ~E_NOTICE);
// #################### DEFINE IMPORTANT CONSTANTS #######################
define('THIS_SCRIPT', 'test');
define('CSRF_PROTECTION', true);
// change this depending on your filename
// ################### PRE-CACHE TEMPLATES AND DATA ######################
// get special phrase groups
$phrasegroups = array();
// get special data templates from the datastore
$specialtemplates = array();
// pre-cache templates used by all actions
$globaltemplates = array('TEST',
);
// pre-cache templates used by specific actions
$actiontemplates = array();
// ######################### REQUIRE BACK-END ############################
// if your page is outside of your normal vb forums directory, you should change directories by uncommenting the next line
// chdir ('/path/to/your/forums');
require_once('./global.php');
// ################################################## #####################
// ######################## START MAIN SCRIPT ############################
// ################################################## #####################
$navbits = construct_navbits(array('' => 'Test Page'));
$navbar = render_navbar_template($navbits);
// ###### YOUR CUSTOM CODE GOES HERE #####
$pagetitle = 'My Page Title';
// ###### NOW YOUR TEMPLATE IS BEING RENDERED ######
$templater = vB_Template::create('TEST');
$templater->register_page_templates();
$templater->register('navbar', $navbar);
$templater->register('pagetitle', $pagetitle);
print_output($templater->render());
?>
You're halfway there...
Now go to your Admin CP -> Style Manager
Choose your style and choose to "Add New Template" from the drop down box'...
Give the template the title: TEST
And paste call the code below into it and hit save.
{vb:stylevar htmldoctype}
<html xmlns="http://www.w3.org/1999/xhtml" dir="{vb:stylevar textdirection}" lang="{vb:stylevar languagecode}" id="vbulletin_html">
<head>
<title>{vb:raw vboptions.bbtitle} - {vb:raw pagetitle}</title>
{vb:raw headinclude}
{vb:raw headinclude_bottom}
</head>
<body>
{vb:raw header}
{vb:raw navbar}
<div id="pagetitle">
<h1>{vb:raw pagetitle}</h1>
</div>
<h2 class="blockhead">Title</h2>
<div class="blockbody">
<div class="blockrow">
Text here. Text here. Text here. Text here. Text here.
</div>
</div>
{vb:raw footer}
</body>
</html>
That's in you're done, you now have a custom page, go to your forum url/test.pho and you'll see it.
Finally you can easily add it to your footer by going to the Admin CP -> Options -> Site Name / URL / Contact Details
In there near the bottom there is already a field, usually empty, for the URL to your Terms of Service.