NOTES:
IF YOU ARE RUNNING A “HISTORIC” VERSION OF PORTAINER (IE OLDER AND 1.23.X) PLEASE EITHER FIRST UPGRADE TO 1.24.1 AND/OR BACKUP YOUR PORTAINER.DB FILE BEFORE ATTEMPTING TO UPGRADE TO CE 2.0; THERE ARE REPORTED ISSUES OF DB CORRUPTION WHEN ATTEMPTING TO UPGRADE FROM SUCH AND OLD VERSION TO LATEST IN ONE STEP.
Since you must explicitly remove the portainer container to build it again, maybe it is safe to adjust to portainer-ce and wait the system administrator decides when he wants to force the upgrade