OK, I understand now.
You need a new functionality that would work like this:
Read a usernames or emails list (selectable) and perform one of the available bulk actions on the list.
This would be similar to a delete users by importing a list of emails but with extended functionality.
We'll add this feature in version 2.0 which is expected within 2 weeks.
If you have a user related field in database that would determine new user role you could run this automatically (SQL query based actions) on current version 2.0 RC version.
Should you be interested please email support@ with proof of purchase and I'll send you new version.