I think there may be a misconception. Sonos doesn’t have music ‘in a library’, it is designed to play your music, from a local library on your PC/Hard Drive/NAS, or stream music from a service. At no point does Sonos ‘store’ any music. 

I’d recommend a factory reset of the speakers, if it wasn’t done before being given to your employer. Then they can add a music library after they’ve set up the speakers again, or stream from any service that is part of Sonos.