Migration from vBulletin to Drupal, password extraction issue

[pcoghlan]

I am a recently added administrator for a site that started life as a forum and has now grown (feature-wise rather than volume) to the point it needs to migrate to a different platform.

The chosen platform is Drupal and I need to import all users/posts to the new site.

The posts should be straight forward enough (I think!) once I have the users created but I am trying to ensure that users simply see a new skin and can log in using their usual username/password once the migration has been completed.

I have full administration access and am thinking there should be a way using SQL to extract or port the users/passwords to the Drupal database?

Has anyone any pointers or done this before?

Thanks,
Paul