[Koha] Koha upgrade from 3.2 to 19.05

Hello, Our library is planning to upgrade Koha from the version 3.2 to 19.05 (latest). Could you please give us a complete tutorial, system requirements, and the things we have to do (backup ?, etc,) before starting the upgrade. Is it possible to upgrade directly from 3.2 to 19.05 ? or we have to upgrade to lower versions before? Best regards, Walid -- *Sultan Qaboos Cultural Center Library* 1100 16th St, NW Washington, DC 20036 library@sqcc.org 202-677-3967, x104