How to parse PHP syntax in a .html file on server?

Question

This feels like an extremely n00b question, but here goes...

I have a series of HTML files with a small amount of HTML content inside each (exported from a live system).

Answer 1

ModRewrite

RewriteEngine on
RewriteRule ^(.*).html$ $1.php

AddType

AddType application/x-httpd-php .htm .html