CMS2CMS Migration Plugins: Why and How Tumblr to Wordpress Plugin | Page 4
How to Prepare for Migration?
1. Back up your Tumblr website
2. Install WordPress
3. Set up custom URL structure for WP
4. Find FTP access details (for Tumblr and WordPress)
Find more info in this article
http://wordpress.org/plugins/cms2cms-automated-tumblr-to-wp-migration/