This article describes the steps for upgrading a hypervisor tools version in a Citrix Provisioning environment.
Use the following procedure to upgrade a Hypervisor:
1.     Reverse image the vdisk.
2.     Boot from the local HDD on the VM that has been reverse imaged to.
3.     Uninstall the PVS target device software.
4.     Upgrade hypervisor tools.
5.     Reinstall Provisioning Services target software.
6.     Create image of updated machine.
Note: When the image has been tested in private mode, the vDisk can be changed into standard mode to be used by all assigned target devices.