Moving a licence to another computer

While setting up 2 classrooms with PC’s, we have mistakenly activated licences on PC’s that were already activated. Why Cubase doesn’t say there is a licence install already is beyond me! We now have 2 licences showing in eLicencer for the same product. The option to remove a licence is greyed out. Is it possible to remove one of them so that it can be added to another PC? Being in a classroom the USB eLicencer option isn’t viable.