Best approach for migrating all Jira projects from group-based permissions to role-based

[Svetlin]

Greetings Atlassian Community!

My team has decided to move away from Jira Group-based projects to role-based ones. The name of the task: 

"Migrate all Jira projects from group-based permissions to role-based"

Would you like to share some ideas and a basic algorithm as to how can this be done in the most effective and correct way in accordance with best practices?

 BR

[Svetlin]

Having a list of default templated schemes, I am thinking, would it be a good idea to remove the groups from the templates? 

Is there an automated API approach to remove all groups from the permission schemes?