How To Remove Xen Guest from DOM0

1 - SSH into the Dom0 (the host machine).

2 -
$ xm list | grep <DomU> 
where <DomU> is the short hostname of the virtual machine, e.g. yoyodyne. The DomU to be decommissioned should not be listed. If it is, execute

$ xm destroy <DomU> 
This command force shutdowns the VM

3 - Remove the auto-boot symlink:
$ rm /etc/xen/auto/<DomU>.cfg 

4 - Remove the Xen domain configuration:
$ rm /etc/xen/<DomU>.cfg 

5 - Remove all logical volumes associated with the domU. In most cases this will consist of a single LV:
lvremove /dev/<Dom0>/<DomU>-<device> 

For example:
lvremove /dev/dom0server/yoyodyne.example.com-hda