1. Get Wordpress
  2. Install it locally, or somewhere you don’t care about it
  3. Make whatever modifications to the Index Template and Stylesheet you want
  4. Make sure you have a local copy of everything you want to keep or use
  5. Uninstall MT & clear your blog directory (or just move it, how lucky are you feeling?)
  6. Install Wordpress in your blog directory (you may have to clear a database or two first)
  7. Upload the index.php and wp-layout.css files you prepared earlier – along with any other bits and pieces you need for them to work
  8. Import your MT entries
  9. Set up Permalink Redirects
  10. Tweak to your heart’s content