That's album is associated with the Apple/iCloud ID and password you used to enable the Share Photo Albums and manage. That ID will also be linked to any purchases you have made from the App Store, iTunes Store or the Apple Online Store.
1 - Therefore, you may want to create a new Apple ID just for the school. Then on your Mac log out of iCloud and log back in with the new Apple ID. You'll have to recreate the shared albums with that ID using the current library and re-invite the teachers again. You should have all of the photos from the Shared Album in the Photos library. If not then download them and add to the library before switching.
2 - Once you have the new shared album(s) up and running you an delete the existing ones.
3 - Now when you turn the library over to the IT pro, they can create a new "school photo" user account on their Mac, log into iCloud with the new school Apple ID that you created. You'll have to copy the library to the "school photo" user account on the IT Mac and set it as the System Photo Library. The IT pro will then have control of the shared libraries from that special user account.
