You can try using the Change stage utility to transition from Alternate stage to Primary stage in the Case life cycle. But it will start from the first step of the stage which you have mentioned in the Change stage.
Thanks yerrh for your response. I am looking for going back to primary stage same step or next step previously I was in. You mentioned start from the first step of the stage.
I have found one OOTB activity GoToPreviousTask, This activity takes TaskName as parameter, so, by specifying Task Name, can we go back to particular task which is in primary stage and it has a entry point enabled?