For the BYOL model, you can migrate from Oracle SE2 to Oracle Enterprise Edition as long as you possess an unused license appropriate for the edition and the class of DB service you plan to run. You cannot go from Enterprise Edition to other editions. To change the edition and retain your data, you should take a snapshot of your running DB service and then create a new DB service of the desired edition from that snapshot. You can then delete the old DB service unless you wish to keep it running and have the appropriate Oracle Database licenses.