I am the Treasurer for several Not For Profit community organisations and use Manager to manage all of them because it is a free system. If somone else is elected to take over as the treasurer of any of the organisations can they download the software and transfer the files to their computer. The system will always continue to be a single person access system.
Yes, once they have installed Manager, just click Add Business + Import Business and they can load the file you have provided them with.
Read this Guide for detailed procedures: Backup, restore, import, and transfer businesses | Manager.