Hi
basically, subscription management is rather easy: as you already have user groups, you just use these groups to assign them in the subscription management app. Therefore, you do not really "transfer" a license - you just remove users who don't need any more of a subscription from the configured user group or add users who should inherit licensable roles.
If you want to know it in more detail, please download my Knowledge Sources To Go. You will find in that document many links to helpful resources regarding subscription management.
Maik
