You would need to import your users into vbulletin Want to go from standalone to Vbulletin in Photopost?
Then you can do the steps outlined here
1. Do your forum stuff that has nothing to do with our product imports etc
2. Edit the settings table of Photopost settings 41,83,171-173 and set to the proper integration type forum mysql table prefix and cookie settings.
3. Edit your config-inc.php file of Photopost and enter in user database the proper vbulletin mysql info and the proper vbulletin license in the $vblicense variable line.
4. In your usergroups table of Photopost delete all entries except Administrators where that one you want to edit it and change the groupid from 2 to 6
You should then be able to login with your vbulletin admin and import usergroups and set the enhanced vb3 integration stuf