This script lets you import your old DragonByte SEO configuration and have any supported URLs redirected to XF2. Which URLs are supported depends on the XenForo Redirects for vBulletin script.
Install the addon, import the old DB via the importing interface, and you're done. It works entirely in the background with no additional configuration needed. MAGIC.
Read The Fabulous Manual on the FAQ tab to see the answers to (what I imagine will be) common questions.