@mattnj
In case anyone else runs into this issue, it was the oldest solution in the book. Reboot the server. Then the vm instances deleted instantly with the vm-destroy command.

In attempting to install XOA through the Web workflow, 3 instances of the XOA vm were created. I am unable to delete any of these instances. I have tried using the XOLite GUI and "xe vm-destroy uuid:<the uuid of the vm> without success. In both cases the operation appears to start but then hangs indefinitely without any sign of activity. CPU stays flat. Should this operation take a long time, or have I missed something?

Thanks!