You can upgrade the App Volumes agent to the latest available version, and if your current installed version is App Volumes 2.12, you do not need to uninstall it before upgrading.
You can also upgrade the agent silently. See Upgrade App Volumes Agent Silently.
Prerequisites
Download the latest App Volumes installer from My VMware.
Schedule a maintenance window to ensure that there is no service degradation during the uninstall and subsequent upgrade process.
Upgrade the App Volumes Manager. See Upgrade App Volumes Manager.
Unassign all AppStacks and writable volumes from the target computer where you plan to upgrade the agent.