Okies, so never made a plugin before, but I gave it a go and this is what I wrote:
----------------------------------------------------------------------
<?php
/*
Plugin Name: Blog to Website
Description: Changes any occurrence of the word blog to website.
Version: 1.0
Author: Jessica E.
*/
?>
<?php
function blog_to_website($content) {
global $blog;
$content=str_ireplace($blog,'{website}',$content);
return $content;
}?>
<?php
apply_filters('blog_to_website',__('blog'));
?>
----------------------------------------------------------------------
Of course it doesn't work since this is too advanced for me! The directions in the link you gave me said:
1. Create the PHP function that filters the data.
2. Hook to the filter in WordPress, by calling add_filter()
3. Put your PHP function in a plugin file, and activate it.
I's my function all messed up?