If you're serious you'll have to re-build from scratch.
Wordpress sites are made of snippets of PHP code which pull content from a database and compile pages on the fly. It's very complex code so it's best to take your content and start again in DW.
Any reason for doing this? Most people do exactly the opposite since Wordpress allows multi-author, browser-based editing, single click theme swapping and thousand of easy to use add-ons to add functionality to your site in seconds which are complex to code manually.
I can't see any up side to moving away from a dynamic site in Word Press to a static one in Dreamweaver. Have you thought this through? Are you absolutely certain your current site is not going to fall apart when you remove it from WordPress & the MySQL databases and PHP scripts? For example, do you use your site for blogging or e-commerce?
If you're sure you really want to do this, use your browser to copy & paste old content into a new Dreamweaver site.