Prior to any upgrade, save a backup of your current configuration (Administer/Backup), and add your current version digits to the filename to remind you what version it came from.
ie. GWehe-ZD1112_db_983014_111715_16_10.bak (if you were on 9.8.3.0.14)
Second, read the Release Notes for the ZD 9.10.1 version you intend to upgrade to, and make sure all your AP models are supported.
Some Legacy APs like 2942/7942 are EoS.
https://support.ruckuswireless.com/documents/830-zoneflex-9-10-1-mr-release-notes Then, from Administer/Upgrade, you click the Browse button and load the image you have downloaded to your PC,
and when prompted to save a backup, you can skip, and click Upgrade to continue.
The ZD will upgrade and reboot. Your APs will reconnect and each get upgraded to the new ZD firmware version.
Watch from Monitor/Access Points page, as they go from upgrading firmware, disconnected, provisioning, to Connected.
A typical ZD1100 upgrade shouldn't take more than 15-20 minutes.