Can I change the AccessRights to a Group?

Hello, I know we can set an UserGroup AccessRights with the method SetAccessRights.

But can i do the same from  a Group? I noticed the method does not exist for groups.

I am trying to do a script that changes the AccessRights of a usergroup to a specific group.

The reason for this is because i am pretty much "cloning" the access rights from a Old DB to a New DB, using an excel where i only have the old GUIDs of usergroups and the new GUIDS of the new usergroups.

When I run the script I always need to choose a Main Group from a DB.

I do try to use inherit to change the access rights of the groups but in the end I am just changing the Main.

Please tell me if there an easier way to change AccessRights of Groups.