Out of curiosity can I also ask why?
The virtual appliance is our OVA with the pre-installed software. Which I believe is possible to upgrade lets say from 3.5 to 3.5 CRx. Where the 4.0 Portal EE is completely different and a whole different process and software.
What is the end goal of the Portal removal? And what version are you trying to go from -> to?
Thanks..