There is no direct way to ‘convert’ an old site. If you did attempt it, there would be much customized programming needed to grab data from the CF pages into the WordPress site. It can be done, but I don’t know if the effort is worth it.
It all depends on the site content. If this were my project (I have CF and WP experience), and it is a ‘static’ type of site (content only, no data access), I’d first build a WP site with the theme and ‘look’ that was needed. I’d grab some content (via text copy/paste) from the CF site, and create new pages on the WP site.
If there is much data-driven content, with the data being ‘live’ (changes over time), then perhaps a WP site is not the best choice. In that case, I’d build a PHP-based site, with access to the data as needed.
So, you’d need someone that knows CF and WordPress, and maybe additional PHP and data access skills. And a big budget, as it might require much effort to do.
It depends on what the old site ‘does’, and whether it needs to access data, or you just need to duplicate a static-content site.
In any event, good luck! Hope this helps.