How to re-import all posts/comments/content from WordPress.com to WordPress.org?

We currently have a WordPress.com blog, and are revisiting a project to move to a self-hosted WordPress.org blog. We originally installed WordPress.org on our server and imported the current blog content back in early 2013, I believe. The project then got de-prioritized for a while, and I’m now being asked to work on it again. Obviously, we’ve been continuing to post to our WordPress.com blog in the meantime, so the question now is, what’s the best way for me to freshen the content on the self-hosted version?

It seems like, from this post — http://wordpress.org/support/topic/how-do-i-re-import-overwriting-all-postscomments — that it may be easiest to delete all the content from the database and reimport from scratch, but, since that post was four years old, I thought I’d ask if there were a better way to do this now?

If not, does anyone have more detailed instructions (including the appropriate DB drop script, if readily available) on how to re-import blog content from WordPress.com to WordPress.org, freshening up what’s already there? It’d be much appreciated, thanks!