Convert Wordpress User Database to Joomla

Hello there-- I'm preparing to convert a website from a wordpress database to a joomla CMS with a PHPBB bridge. The wordpress database currently has over 600 members and forum posts; the membership records will need to be relocated to Joomla and their forum posts will need to be transferred as well. It should not be difficult for anyone with experience in SQL or database design. The current CMS and forum is called Wordpress and Simple Press Forum. It should be converted to Joomla and PHPBB. The person for the job will need to have the highest level of integrity as they deal with sensitive passwords and email addresses.