From the manual: This must be done through the host software which takes control of the Z-Stick USB adapter while the Z-Stick is in SerialAPI-Mode.
If you have the Danfoss ZWave PC Controller, previously available here, you can use the “Reset Controller” button to do so. This works fine in VMware Player too, so you don’t need to install a bunch of stuff on your main machine.
Here are a couple of files to help you out 🙂
Aeon Z-Stick S2 Manual
Windows Driver
Latest Firmware (as of 2014-08-10)
Danfoss ZWave PC Controller v1.0.5