How to use the Vanilla Commenting System with WordPress
1. If you had previously used the Vanilla Embed plugin, disable it by following the instructions posted here: http://blog.vanillaforums.com/converting-embed-plugin/
2. In your forum Dashboard, click on ‘Blog Comments’ and enable embedding.
3. Login to WordPress and under ‘Plugin’ select ‘Add New’ and search for ‘Vanilla Forums’. Install the plugin and activate it. A new menu item will be displayed on the menu bar called ‘Vanilla Forum.’
4. Under the ‘Vanilla Forum’ menu select ‘Setup’ and enter the URL of your forum, e.g. http://yourforum.vanillaforums.com
5. Under ‘Comment Integration’ check Replace your blog’s native commenting system with Vanilla comments and select the forum category where you would like comment discussions to appear. If you would like to direct comment discussions to different categories, you’ll have to modify the WordPress template and use the Vanilla Comments Universal Code instead of the WordPress plugin. This will require a bit of programming to map the WordPress category to the Vanilla category.