MDW

Hi All, I have taken over this program at a school and every time I try to enter a licence it comes up with exceeded the user licence count. Now from what I can work out, the program was deployed to a class last year, since then the computers imaged without the Kerbal Space program being uninstalled / licence revoked. Does anyone have an answer on resetting our licences so we can get it running for a next class or would I need to purchase more licences? Thanks, MDW