What is the process to Migrate the security, users and gropus from BO 3.1 to 4.1

Dear All,

Please help me to find a way to migrate the security , users and groups from BO 3.1 to 4.1.

If we are able to migrate the security from BO 3.1 to 4.1 ,will be able to get 100 % security from 3.1

what are the things we need to take care for security migration .

or do we need to rework on 4.1 Security as similar to BO 3.1

Thanks In Advance